Ch19,20,21

Question 1

“At least ___ types of populations must be considered when preparing to collect data ” What are they?

Answer 1

“At least four types of populations must be considered when preparing to collect data ”
-Target population
-Source population
-Sample population
-Study population

Question 2

“The broadest group is the ____ population, the broad population to which the results of a study should be applicable.”

Answer 2

target population: (the general population that the study seeks to understand )

Question 3

“The ____ population, sometimes called a sampling frame, is a well-defined ____ of individuals from the target population from which potential study participants will be sampled.”

Answer 3

“The source population, sometimes called a sampling frame, is a well-defined subset of individuals from the target population from which potential study participants will be sampled.”

Question 4

“The ___ population consists of the individuals from a source population who are ____ to participate in the research project. When a ____ population is ____, everyone might be ______ to participate. When a source population is very large, only a small ____ of _____ might be ______ for a study.”

Answer 4

“The sample population consists of the individuals from a source population who are invited to participate in the research project. When a source population is small, everyone might be invited to participate. When a source population is very large, only a small subset of members might be recruited for a study.”

Question 5

“The _____ population comprises the eligible members of the sample population who _____ to participate in the study and complete ______ study activities.”

Answer 5

“The study population comprises the eligible members of the sample population who consent to participate in the study and complete required study activities.”

Question 6

“19.3 Sample Populations

When the _____ _______ is small, every person who is listed as a member of the _____ population can be asked to participate in the study. When that approach is used, the ____ population is the same as the ______ population. However, a source population is often much ___than the sample size required for a study. When the source population is large, a subset of the source population may serve as a sample population.”

Answer 6

“19.3 Sample Populations

When the source population is small, every person who is listed as a member of the source population can be asked to participate in the study. When that approach is used, the source population is the same as the sample population. However, a source population is often much larger than the sample size required for a study. When the source population is large, a subset of the source population may serve as a sample population.”

summary: when source pop is small, can be used as the sample pop…when source pop is larger than the sample pop, the sample is a subset of the source pop.

Question 7

“Bias is a ________ problem in the ___, ____, or ____ of a study that can cause the results of the study to be erroneous. Many types of bias are related to the sampling process used for a study. ”

Answer 7

“Bias is a systematic problem in the design, conduct, or analysis of a study that can cause the results of the study to be erroneous. Many types of bias are related to the sampling process used for a study. ”

Question 8

“Many types of bias are related to the ____ process used for a study.”

Answer 8

“Many types of bias are related to the sampling process used for a study.”

Question 9

“ ______bias (or ascertainment bias) occurs when the individuals sampled for a study systematically are not representative of the source population as a whole. ”

Answer 9

“ Sampling bias (or ascertainment bias) occurs when the individuals sampled for a study systematically are not representative of the source population as a whole. ”

Question 10

“ _____ bias occurs when each individual in the source population does not have an equal chance of being selected for the sample population.”

Answer 10

“ Nonrandom-sampling bias occurs when each individual in the source population does not have an equal chance of being selected for the sample population.”

Question 11

“A variety of _____-______ sampling methods can be used to ensure that all members of a source population have an equal likelihood of being invited to participate in a research study. Examples of some of these types of probability-based samples are shown in Figure 19-2:
-simple random sampling…..
-systematic sampling…..
-stratified sampling….
- cluster sampling….

Answer 11

“A variety of probability-based sampling methods can be used to ensure that all members of a source population have an equal likelihood of being invited to participate in a research study. Examples of some of these types of probability-based samples are shown in Figure 19-2:
-simple random sampling:
each person has an equal chance of being selected
-systematic sampling:
after random start point, every nth person is selected
-stratified sampling:
simple random sampling is selected from each of several strata
-cluster sampling:
area is divided into geographic clusters and some clusters are selected for inclusion

Question 12

“Probability-based sampling is usually the preferred option for producing a sample population that is ____ to the source population as a whole. ”

Answer 12

“Probability-based sampling is usually the preferred option for producing a sample population that is similar to the source population as a whole. ”
-if they are not similar then this would represent non-random sampling (where sample pop doesn’t adequately represent the source population as a whole)

Question 13

“If a list of every individual in the ____population is available, a computer program can select at random the individuals who will be invited to participate. ”
What type of sampling does this represent?

Answer 13

“If a list of every individual in the source population is available, a computer program can select at random the individuals who will be invited to participate. ”
-(simple random sampling)

Question 14

“If participants are being sampled from the ____ ____ of a national professional organization, every 10th person could be contacted.”
What type of sampling does this represent?

Answer 14

“If participants are being sampled from the membership list of a national professional organization, every 10th person could be contacted.”
-(systemic sampling) note: no order, random start

Question 15

“If 12 colleges are participating in a health behavior study, the ___ percentage of students from each school could be randomly sampled for the study.”

Answer 15

“If 12 colleges are participating in a health behavior study, the same percentage of students from each school could be randomly sampled for the study.”

Question 16

“If a cross-sectional study will draw participants from a large geographic area, ____ sampling might be used. ”

Answer 16

“If a cross-sectional study will draw participants from a large geographic area, cluster sampling might be used. ”

Question 17

“Whole city blocks could be randomly sampled for inclusion in the sample population, and ___of people who live on those blocks could be asked to participate.”

Answer 17

“Whole city blocks could be randomly sampled for inclusion in the sample population, and 100% of people who live on those blocks could be asked to participate.”

Question 18

“Alternatively, the sample population might consist of all residents in the city who live on every 7th street that runs north to south, starting with a randomly sampled street.”

Answer 18

this represents systemic sampling

Question 19

“Sometimes a nonprobability-based sample is appropriate. A ______ population is a nonprobability-based source population selected due to ____of access to those individuals, schools, workplaces, organizations, or communities. ”

Answer 19

“Sometimes a nonprobability-based sample is appropriate. A convenience population is a nonprobability-based source population selected due to ease of access to those individuals, schools, workplaces, organizations, or communities. ”

Question 20

“Convenience sampling must always be used with _____, since convenient sample populations are often systematically _____ from the target and source populations they are intended to _____. Even if a probability-based sample is drawn from a convenience source population, the sample is unlikely to be representative of the target population as a whole. ”

Answer 20

“Convenience sampling must always be used with caution, since convenient sample populations are often systematically different from the target and source populations they are intended to represent. Even if a probability-based sample is drawn from a convenience source population, the sample is unlikely to be representative of the target population as a whole. ”

Question 21

For example, samples “based on a patient population or an occupational population are _____ to represent health status in the cities and towns where those individuals reside.”

Answer 21

“based on a patient population or an occupational population are unlikely to represent health status in the cities and towns where those individuals reside.”

Question 22

“No matter which sampling method is used, the goal is to end up with a ______ population that is representative of the ______population and, ideally, of the ____ population, too.”

Answer 22

“No matter which sampling method is used, the goal is to end up with a sample population that is representative of the source population and, ideally, of the target population, too.”

Question 23

“Being aware of common types of bias enables a researcher to make informed decisions about source populations. For example, ______bias can occur when cases and controls for a study are recruited from hospitals and therefore are more likely than the general population to have comorbid conditions. ”

Answer 23

“Being aware of common types of bias enables a researcher to make informed decisions about source populations. For example, Berkson’s bias can occur when cases and controls for a study are recruited from hospitals and therefore are more likely than the general population to have comorbid conditions. ”

Question 24

“ _____ ______ bias can occur when participants are recruited from occupational populations and therefore are systematically healthier than the general population. ”

Answer 24

“ Healthy worker bias can occur when participants are recruited from occupational populations and therefore are systematically healthier than the general population. ”

Question 25

“____ ____ occurs when different eligibility criteria are applied to cases and controls, such as when controls with health conditions related to an exposure are excluded but cases with those comorbidities are not excluded.”

Answer 25

“Exclusion bias occurs when different eligibility criteria are applied to cases and controls, such as when controls with health conditions related to an exposure are excluded but cases with those comorbidities are not excluded.”
-For example, if patients died from toxic effects of an experimental treatment and were subsequently excluded from the trial analysis, perhaps as ‘early deaths’, the estimate of effect would be biased in favour of that experimental treatment.

Question 26

These study design “may result in ____ bias if the members of a sample population who agree to participate in a study are systematically different from nonparticipants.

Answer 26

“may result in nonresponse bias if the members of a sample population who agree to participate in a study are systematically different from nonparticipants.

Question 27

However, a less than 100% participation rate is usually not a problem as long as the researcher:”

Answer 27

“Uses acceptable and carefully explained sampling methods
Takes appropriate steps to maximize the participation rate
Recruits an adequately large sample size
Reports the number of potential participants at each stage
Even so, researchers should develop a recruiting strategy that will encourage a high rate of participation.”

Question 28

“19.5 Populations for Cross-Sectional Studies”

Answer 28

“19.5 Populations for Cross-Sectional Studies”

Question 29

“The results of cross-sectional studies(observational study design..the investigator measures the outcome and the exposures in the study participants at the same time.)
are often used to make important ______ and ____ _____, so the study population for a cross-sectional study should adequately represent the _____ population.”

Answer 29

“The results of cross-sectional studies are often used to make important resource and policy decisions, so the study population for a cross-sectional study should adequately represent the target population.”

Question 30

“A ______-_______ study uses a random sampling method to generate a sample population that is representative of a well-defined larger population. The strongest cross-sectional surveys are population-based studies that use probability-based sampling rather than a convenience population. The goal is to select a source population that is reasonably representative of the target population and then to sample and recruit a set of study participants who are reasonably representative of the source population.”

Answer 30

“A population-based study

Question 31

“The most rigorous population-based studies use probability-based sampling methods to generate sample populations and then confirm that study populations are reasonably representative of the _____ populations from which they were drawn. ”

Answer 31

source

Question 32

“A ___ is a complete enumeration of a population, such as a count of every resident of a country, the number of inpatients at a particular hospital at noon on a selected day, or the number of employees of a large company.”

Answer 32

census
- count

Question 33

“When a census of the source or _____population has been recently conducted, the ___ and ____ populations for a cross-sectional study should reflect the demographics of that census.”

Answer 33

“When a census of the source or target population has been recently conducted, the sample and study populations for a cross-sectional study should reflect the demographics of that census.”

Question 34

“For example, suppose the goal of a study is to quantify the prevalence of tobacco use among high school students in a county. The county’s 14 high schools together serve as the ______ population and the source population. Selecting only 1 high school as the sample population is probably not sufficient. Working intensely with 1 school might ______ participation rates. However, the selected school might enroll students who are different from county students as a whole—more rural or urban, more or less diverse, or from more or less wealthy households. In such a situation, the results from that one high school would not be an accurate reflection of adolescent health across the county.”

Answer 34

“For example, suppose the goal of a study is to quantify the prevalence of tobacco use among high school students in a county. The county’s 14 high schools together serve as the target population and the source population. Selecting only 1 high school as the sample population is probably not sufficient. Working intensely with 1 school might maximize participation rates. However, the selected school might enroll students who are different from county students as a whole—more rural or urban, more or less diverse, or from more or less wealthy households. In such a situation, the results from that one high school would not be an accurate reflection of adolescent health across the county.”

Question 35

“A better option is to sample some students from each of the 14 schools. For example, 20% of the classes in each high school that meet during the first period of the school day could be randomly sampled, and 100% of the students in those sampled classes could be invited to participate (Figure 19-3). After the data are collected, the researcher can validate the representativeness of the study by confirming that the proportion of students by grade, age, and sex in the study population is similar to the distribution of these characteristics among the county’s total high school student population.”

Answer 35

ok

Question 36

“FIGURE 19-3 Population Example for a Cross-Sectional Study”
Target population: High school students in north county
Source population: All high school students in north county
Sample population: all students in 20% of homerooms in all high school students in north county
1.Study approach
2.Study question
3.Data collection method
4.Target population
5.Source population
6.Source population list
7.Sample population
8.Study population
9.Confidentiality

Answer 36

1.Study approach
Cross-sectional study(observational study design..the investigator measures the outcome and the exposures in the study participants at the same time.)
2. Study question
-“What proportion of high school students in North County smoke cigarettes?”
3. Data collection method
-Participants will complete their own paper-based questionnaires.
4. Target population
-“Students in grades 9–12 in North County”
5. Source population
-“All students enrolled in any of the 14 high schools in North County”
6. Source population list
-“A list of the number of students in each homeroom provided by each high school”
7.Sample population:
-“Based on estimated sample size requirements, 20% of homerooms will be randomly sampled from the lists provided, and all students in these sampled homerooms will be asked to participate in the study.”
8. Study population:
-“Eligible individuals from the sample population who agree to participate”
9. Confidentiality
-“No student names will ever be provided to researchers; surveys will be anonymous.”

Question 37

“When census data are __ _____ for a ____or target population, careful planning can help a researcher recruit a study population that is reasonably representative of the target population. Recruiting participants for a general population survey from among the spectators at a football game, the shoppers in a particular grocery store, or the donors at a volunteer blood drive will likely result in a _____ population that does not represent the target population. Convenience populations are not suitable for most cross-sectional studies because they are not population-based.”

Answer 37

“When census data are not available for a source or target population, careful planning can help a researcher recruit a study population that is reasonably representative of the target population. Recruiting participants for a general population survey from among the spectators at a football game, the shoppers in a particular grocery store, or the donors at a volunteer blood drive will likely result in a sample population that does not represent the target population. Convenience populations are not suitable for most cross-sectional studies because they are not population-based.”

Question 38

19.6 “Populations for Case–Control Studies”

Answer 38

yes

Question 39

“When identifying possible participants for a case–control study, the first step is to find ….

Answer 39

an appropriate and available source of cases.

Question 40

“All cases must have the ___ disease, disability, or other health-related condition.”

Answer 40

same

Question 41

“The study’s case definition should be very clear about the ______that must be ____ and _____ for an individual to be categorized as a case. For example, a researcher may want to select only candidates with advanced disease or, alternatively, may prefer to study only cases whose symptoms began recently. The case definition should specify both the inclusion and the exclusion criteria. The case and control definitions for a study can be written to exclude borderline cases from serving as either cases or controls.”

Answer 41

“The study’s case definition should be very clear about the characteristics that must be present and absent for an individual to be categorized as a case. For example, a researcher may want to select only candidates with advanced disease or, alternatively, may prefer to study only cases whose symptoms began recently. The case definition should specify both the inclusion and the exclusion criteria. The case and control definitions for a study can be written to exclude borderline cases from serving as either cases or controls.”

Question 42

“Hospitals, specialty clinics, public health offices, disease support groups, and advocacy organizations may be helpful resources for locating individuals or groups of individuals who are likely to meet the study’s case definition. However, care must be taken to ensure that the ____population is not healthier, sicker, or more or less socially connected than the typical person who meets the case definition. ”

Answer 42

“Hospitals, specialty clinics, public health offices, disease support groups, and advocacy organizations may be helpful resources for locating individuals or groups of individuals who are likely to meet the study’s case definition. However, care must be taken to ensure that the sample population is not healthier, sicker, or more or less socially connected than the typical person who meets the case definition. ”

Question 43

“Another option may be to conduct a _____ ___-___ study that uses the participants of a large longitudinal cohort study as the source population for both cases and controls. A _____ design minimizes ___ bias because data about past exposures were collected at the time of the exposure and are not based on participants’ ______. However, a cohort study will yield a sufficient number of cases only when the disease being studied is relatively ____.”

Answer 43

“Another option may be to conduct a nested case–control study that uses the participants of a large longitudinal cohort study as the source population for both cases and controls. A nested case–control study design minimizes recall bias because data about past exposures were collected at the time of the exposure and are not based on participants’ memories. However, a cohort study will yield a sufficient number of cases only when the disease being studied is relatively common.”

Question 44

“Once a source of cases is identified, a valid ____ group must be selected. The _____ must be ____ to the cases in every way except for their _____ status.

-For example, it would be inappropriate to compare cases with heart disease to controls who are marathon runners. A study examining a chronic disease should choose a control population representative of the general public, not a population that is unusually physically active. Similarly, it would be inappropriate to compare older adult women to teenage boys, or to compare big-city businessmen to men who are subsistence farmers in remote areas. All cases and controls for any one study should come from ___ sociodemographic and geographic source populations.”

Answer 44

“Once a source of cases is identified, a valid control group must be selected. The controls must be similar to the cases in every way except for their disease status. For example, it would be inappropriate to compare cases with heart disease to controls who are marathon runners. A study examining a chronic disease should choose a control population representative of the general public, not a population that is unusually physically active. Similarly, it would be inappropriate to compare older adult women to teenage boys, or to compare big-city businessmen to men who are subsistence farmers in remote areas. All cases and controls for any one study should come from similar sociodemographic and geographic source populations.”

Question 45

“Many _____ types of populations may be suitable sources of controls for a case–control study. For some hospital-based studies, it may be appropriate to use as controls individuals hospitalized with a condition other than the one being studied. For some population-based studies, random-digit telephone dialing may yield a representative population—or, because many people will refuse to answer personal questions over the telephone, this strategy may result in a very unrepresentative population. In some situations, friends or family members of the cases may be the best controls because they are likely to have sociodemographic characteristics similar to the cases. When making this important decision, the researcher should consider the possibilities for matching cases to controls using group or individual matching.”

Answer 45

“Many different types of populations may be suitable sources of controls for a case–control study. For some hospital-based studies, it may be appropriate to use as controls individuals hospitalized with a condition other than the one being studied. For some population-based studies, random-digit telephone dialing may yield a representative population—or, because many people will refuse to answer personal questions over the telephone, this strategy may result in a very unrepresentative population. In some situations, friends or family members of the cases may be the best controls because they are likely to have sociodemographic characteristics similar to the cases. When making this important decision, the researcher should consider the possibilities for matching cases to controls using group or individual matching.”

Question 46

“The eligibility criteria for a study comprise the inclusion criteria that must be present for an individual (or, for a systematic review, a research manuscript) to be allowed to participate in a study and the exclusion criteria that require an individual (or manuscript) to be removed from the study population. All cases and all controls in a case–control study must meet the same eligibility criteria, except for the ones relating to disease status. For example, a study targeting septuagenarian women should require both cases and controls to be women in their 70s who live in the same general area”

Answer 46

“to participate in a study and the exclusion criteria that require an individual (or manuscript) to be removed from the study population. All cases and all controls in a case–control study must meet the same eligibility criteria, except for the ones relating to disease status. For example, a study targeting septuagenarian women should require both cases and controls to be women in their 70s who live in the same general area”

Excerpt From: Jacobsen, Kathryn H.;. “Introduction to Health Research Methods.” Apple Books.

Question 47

“FIGURE 19-4 Population Example for a Case–Control Study”

Target population: American women ages 70-79
Source population: All women ages 70-79 years admitted to St lukes hospital system in central city with an incident hip fracture in the past 12 months (cases) and their friends (control)
Sample population:All women ages 70-79 years admitted to St lukes hospital system in central city with an incident hip fracture in the past 12 months (cases) and 3 friends per case (control)
1. Study approach
2. Study question
3. Data collection method
4. Target Population
5. Source population (cases)
6. Source populations list
7. Sample populations (cases)
8. Source population (controls)
9. Sample population (controls)
10. Study population
11. Confidentiality

Answer 47

1. Study approach
   Case–control study
2. Study question
   “What are the risk factors for hip fractures in adult women in the United States?”
3. Data collection method
   participants will be interviewed in person or by telephone
4. Target Population
   “Women ages 70–79 years living in the United States”
5. Source population (cases)
   “All women ages 70–79 who were admitted to St. Luke’s Hospital System in Center City with an incident (new) hip fracture in the past 12 months”
6. Source populations list
   “A list of the hospital registration numbers for each inpatient female ages 70–79 at admission whose electronic medical record indicates a diagnosis of a hip fracture (ICD10 code S72) during the eligible 12-month period”
7. Sample populations (cases)
   “All members of the source population for cases will be asked to participate in the study.”
8. Source population (controls)
   “Each case will be asked to provide the names of three female friends in the same age range who live in the same county and might be able to serve as controls.”
9. Sample population (controls)
   “All of the friends listed by cases in the study will be invited to serve as controls.”
10. Study population
    “Eligible individuals from the sample populations who agree to participate”
11. Confidentiality
    “The hospital will provide the researcher with the names, addresses, and phone numbers of potential case participants. Personally identifying information will not be included in the electronic file that contains questionnaire responses.”

Question 48

“19.7 Populations for Cohort Studies”

Question 49

“The sampling methods used for a cohort study must align with the particular type of study design that will be applied.
Some longitudinal studies follow a ____-___ sample of individuals forward in time. For longitudinal cohort studies, the process of identifying representative source and sample populations is ___ to the process for identifying these populations for a cross-sectional study. The researchers should try to recruit a ___ study population in order to retain as many participants as possible for the duration of the study. Some longitudinal studies are case series that follow individuals with a particular health condition ___ in time (Figure 19-5).”

Answer 49

“The sampling methods used for a cohort study must align with the particular type of study design that will be applied.
Some longitudinal studies follow a population-based sample of individuals forward in time. For longitudinal cohort studies, the process of identifying representative source and sample populations is similar to the process for identifying these populations for a cross-sectional study.
The researchers should try to recruit a stable study population in order to retain as many participants as possible for the duration of the study. Some longitudinal studies are case series that follow individuals with a particular health condition forward in time (Figure 19-5).”

Question 50

“FIGURE 19-5 Population Example for a Cohort Study”

Target population: all children with cystic fibrosis(CF) in Canada
Source population: all children ages 2-12 years who were patients of the CF clinics of six participating hospitals in the past 12 months
Sample population: 25 % of patients on the source list will be randomly sampled and invited to participate in the study
1. Study Approach
2. Study question
3. Data collection method
4.Target population
5. Source population
6. Source population lists
7. Sample population
8. Study population
9. Confidentiality
“For prospective cohort studies that seek to compare exposed and unexposed populations, identifying exposed and unexposed participants is similar to the steps for identifying cases and controls for a case–control study. For example, studies of the aftereffects of occupational exposures often recruit individuals exposed to on-the-job hazards (similar to cases for a case–control study) through employers, and the researchers then ask those exposed individuals to help recruit unexposed friends and family members to serve as members of the comparison population (similar to the controls for a case–control study).”

Answer 50

1. Study Approach
   Cohort study
2. Study question
   “What is the incidence rate of pneumonia and other lower respiratory infections among children with cystic fibrosis?”
3. Data collection method
   “Participants’ parents will be asked to log all infections throughout the 5-year prospective study period, and these will be checked against the patients’ medical records.”

4.Target population
“All children with cystic fibrosis in Canada”

5. Source population
   “All children ages 2–12 years who were patients of the cystic fibrosis clinics at any of the six participating university-affiliated hospitals in the past 12 months”
6. Source population lists
   “A list of all children ages 2–12 years who were patients of the cystic fibrosis clinics of the six participating hospitals during the past 12 months”
7. Sample population
   “Approximately 25% of the patients on the source population list will be randomly sampled. The parents of sampled children will be asked if they will allow their children to participate in the study.”
8. Study population
   “Eligible individuals from the sample population whose parents consent to participation”
9. Confidentiality
   “All guidelines and regulations for the protection of patient information will be strictly adhered to, and only essential personnel will have access to patient records.”
   “For prospective cohort studies that seek to compare exposed and unexposed populations, identifying exposed and unexposed participants is similar to the steps for identifying cases and controls for a case–control study. For example, studies of the aftereffects of occupational exposures often recruit individuals exposed to on-the-job hazards (similar to cases for a case–control study) through employers, and the researchers then ask those exposed individuals to help recruit unexposed friends and family members to serve as members of the comparison population (similar to the controls for a case–control study).”

Question 51

“19.8 Populations for Experimental Studies”

“Sampling methods for experimental studies focus on the ____ of the study and the ___ of participants.
Validity usually requires a sample population that is reasonably _____ of the target population. For example, suppose that the goal of an experimental study is to test whether nutritional counseling during the first semester at a residential college prevents weight gain during the first year of college. For this intervention study to be valid, the researcher needs to recruit a reasonable cross-section of the first-year student population (Figure 19-6). If the researcher recruited students majoring in nutrition, asked for volunteers, or sampled from among student athletes, the study population would likely be much more concerned about weight than the average first-year student. ”

Answer 51

“Sampling methods for experimental studies focus on the validity of the study and the safety of participants.
Validity usually requires a sample population that is reasonably representative of the target population. For example, suppose that the goal of an experimental study is to test whether nutritional counseling during the first semester at a residential college prevents weight gain during the first year of college. For this intervention study to be valid, the researcher needs to recruit a reasonable cross-section of the first-year student population (Figure 19-6). If the researcher recruited students majoring in nutrition, asked for volunteers, or sampled from among student athletes, the study population would likely be much more concerned about weight than the average first-year student. ”

Question 52

“FIGURE 19-6 Population Example for an Experimental Study”

Target population: First year students attending primarily residential colleges
Source population: All students enrolled in mandatory first-year seminar courses at East State College
Sample population: a randomly selected sample of students from the list of enrolled first-year students
1. Study approach
2. Study question
3. Data collection method
4. Target population
5. Source population
6. Source population list
7.Sample population
8. Study population
9. Confidentiality
“Some experimental studies require participants to be exposed to potentially risky substances or activities.
In such studies, the risk of harm can be reduced by selecting an appropriate ___ population
and defining strict ____ and ____ criteria. For example, studies that involve exercise must target potential participants who are likely to be healthy enough to engage in physical activity. ”

Answer 52

1. Study approach
   Experimental study
2. Study question
   “Does nutritional counseling during the first semester of college prevent weight gain?”
3. Data collection method
   “Half of the participants will be assigned to meet weekly with a nutritionist during their first semester, and half will have no intervention. All participants will complete nutritional assessments during the first and last weeks of the fall and spring semesters of their first year at college.”
4. Target population
   “First-year students at primarily residential colleges”
5. Source population
   “All first-year students at East State College”
6. Source population list
   “A list of all students enrolled in the mandatory first-year seminar class at East State College”

7.Sample population
a randomly selected sample of students from the source population
8. Study population
“Eligible individuals from the sample population who agree to participate”

9. Confidentiality
   “Nutritional counseling and assessment sessions will be conducted in a private setting, and only essential personnel will have access to participants’ records. Participation in the study will be voluntary, and professors teaching first-year seminars will not know which students have enrolled in the study.”

“Some experimental studies require participants to be exposed to potentially risky substances or activities.
In such studies, the risk of harm can be reduced by selecting an appropriate source population and defining strict inclusion and exclusion criteria. For example, studies that involve exercise must target potential participants who are likely to be healthy enough to engage in physical activity. ”

Question 53

“19.9 Sampling for Qualitative Studies”

-“Qualitative data collection is not a detached, structured process based on a ___ sample of individuals.”
-“Instead, researchers typically have ___ contact with a selected group of ____. ”
-“Key informants are….
-Purposive sampling
“For example, focus group participants are typically recruited through purposive sampling because they are able to provide valuable perceptions about the study question. Research projects using focus groups often hold discussions with several different sets of informants. Membership in each group is designed to minimize power differentials and allow for the open sharing of perspectives. A study of workplace safety issues might include separate groups for factory workers who use heavy equipment, their supervisors, and safety engineers at the factory. If supervisors and safety engineers were included in the discussions with the floor workers, it might be difficult for the people operating the machinery to be honest about their concerns. They might feel pressured to provide the answers they thought the company wanted to hear rather than acknowledging the need to address hazards.”

Answer 53

-“Qualitative data collection is not a detached, structured process based on a random sample of individuals.”
-“Instead, researchers typically have intense contact with a selected group of informants. ”
- individuals selected to participate in a qualitative study because they have expertise relevant to the study question.”
-“ is a nonprobability-based sampling method that recruits participants for a qualitative study based on the SPECIAL INSIGHTS they can provide. ”
-“For example, focus group participants are typically recruited through purposive sampling because they are able to provide valuable perceptions about the study question. Research projects using focus groups often hold discussions with several different sets of informants. Membership in each group is designed to minimize power differentials and allow for the open sharing of perspectives. A study of workplace safety issues might include separate groups for factory workers who use heavy equipment, their supervisors, and safety engineers at the factory. If supervisors and safety engineers were included in the discussions with the floor workers, it might be difficult for the people operating the machinery to be honest about their concerns. They might feel pressured to provide the answers they thought the company wanted to hear rather than acknowledging the need to address hazards.”

Question 54

-“Qualitative studies often do not start with a set number of _____ who are supposed to be recruited.
-Instead the goal is to reach data saturation, a time in the research process in which no __ information about a particular theory is emerging from ____ data collection because variations across population members have already been captured.
-Some studies with homogeneous populations might reach saturation after 15 or 20 interviews. Some studies might require larger numbers of participants, especially if they include members with a diversity of perspectives.”

Answer 54

-“Qualitative studies often do not start with a set number of participants who are supposed to be recruited.
-Instead the goal is to reach data saturation, a time in the research process in which no new information about a particular theory is emerging from additional data collection because variations across population members have already been captured.
Some studies with homogeneous populations might reach saturation after 15 or 20 interviews. Some studies might require larger numbers of participants, especially if they include members with a diversity of perspectives.”

Question 55

19.10 Vulnerable Populations
-Vulnerable populations are..
-Examples of vulnerable populations are ….
-should not be selected as…
“ problematic when members of vulnerable populations are systematically ______….
-“Research studies including members of vulnerable populations require extra consideration of the potential risks of research to participants. The study must be sufficiently important to justify gathering new data from members of a vulnerable population. The study must allow every participant (or, for young children and those with significantly diminished cognitive abilities, a legally recognized representative) to provide informed consent free from coercion. Further, it must address concerns about the increased risks of adverse effects from study participation. For example, people with fragile health may have an elevated risk of injury from physical tests, ”

Answer 55

“populations whose members might have limited ability to make an autonomous decision about volunteering to participate in a research study. ”
-“young children, some individuals with serious health issues, people in prison and some other socially marginalized populations, and others who might have limited ability to make an independent decision about volunteering to participate in a research study. ”
-“These populations should not be selected as the source population for studies that do not require their participation”
-“ problematic when members of vulnerable populations are systematically excluded from research, since the only way to study health issues of special importance to potentially vulnerable populations is to allow members of those populations to participate in relevant research studies.”
-“Research studies including members of vulnerable populations require extra consideration of the potential risks of research to participants. The study must be sufficiently important to justify gathering new data from members of a vulnerable population. The study must allow every participant (or, for young children and those with significantly diminished cognitive abilities, a legally recognized representative) to provide informed consent free from coercion. Further, it must address concerns about the increased risks of adverse effects from study participation. For example, people with fragile health may have an elevated risk of injury from physical tests, ”

Question 56

19.11 Community Involvement

“Some studies benefit from or require the participation and support of geographic, cultural, educational, religious, or social communities and their leaders.”
-“A cross-sectional survey that will collect data from students may require the permission of school authorities in addition to the consent of the students and/or their parents and the approval of a research ethics committee. ”
-“A clinical study that seeks to enroll participants with a rare disease may benefit greatly by partnering with an active disease support and advocacy network. ”
-“A longitudinal study that intends to recruit and monitor whole villages will be most successful if formal and informal community leaders and other local representatives are actively involved in planning, recruitment, and retention.”
-“These connections with community representatives should be established early in the research planning process and maintained throughout the data collection and dissemination period.”
- the approval of community leaders does not negate the requirement to obtain individual informed consent from participants whose individual data will be collected. However, community buy-in for a project often facilitates access to source populations and improves participation rates in addition to enhancing the cultural appropriateness of the research protocol and ensuring that the study’s outcomes are valuable to the community.”

Question 57

“CHAPTER 20
Sample Size and Power”
“An adequate number of study participants is required to achieve valid and significant results.”

Question 58

“20.1 Importance of Sample Size”

Answer 58

-“When determining how many participants are needed for a quantitative or qualitative study to be meaningful, the goal is to recruit just the right number of participants—not too many and not too few.”
-“Resources are wasted when a study recruits more participants than it needs.”
-“When study materials, tests, or other implementation activities have a per-participant cost, researchers do not want to spend money on excess participants.”
-“They also do not want to waste the time of the research team or study participants by continuing to collect new data after they already have a sufficient number of participants. ”
-“Resources are also wasted when a study recruits too few participants.”
-“If a primary research project does not collect sufficient data to answer the study question, then all of the time and money invested in the project will have been wasted. ”
-“Most researchers do not have the luxury of worrying about a surplus of participants, but many struggle to “recruit a sufficient study population.
-A shortage can make getting statistically significant results almost impossible.”

Question 59

“20.2 Sample Size and Certainty Levels”

-What is sample size?
-“The desired sample size for a quantitative study is based on _____ estimations about how many data points are ____ in order to answer the study question with a specified level of ____.”
-“___ samples from a population are usually better than small ones at yielding a sample ___ close to the ___ population value. ”

Answer 59

-“sample size is the number of observations in a data set.” (in hs it is number of individual humans in the study population)
-“The desired sample size for a quantitative study is based on statistical estimations about how many data points are required in order to answer the study question with a specified level of certainty.”
-“Large samples from a population are usually better than small ones at yielding a sample mean close to the true population value. ”

Question 60

-“A confidence interval (CI) is a statistical estimate of the range of likely values of a parameter in a _____ population based on the value of that statistic in a ____ population.”
-“A narrow CI indicates more _____ about the value of the statistic than a wide CI.”
-“When the sample size is small, the sample mean might be quite __ from the mean in the total population. ”
-“This is represented by a ___ CI that reaches __ to the left and right of the sample mean.”
-“When a greater proportion of the total population is sampled for inclusion in the estimation of the mean age, the CI for the mean age will be ______ because there is greater certainty about the sample mean being ___ to the population mean.”
-“The 95% CI is calculated for each sample based on the ____ of individuals included in the sample, the ___ age of those individuals, and the ___ ____ of their ages”
-“If __ 20 people in the total population are ___in the analysis, __ CI is required because the population ___ age will be known _____.”

-“For the top line in Figure 20-2, the sample mean is 34 years, and the CI stretches from 18 to 50 years. Based on this sample, a researcher can be 95% confident that the mean age in the total population is somewhere between 18 and 50 years. If hundreds of random samples of 3 individuals are drawn from the total population of 20, about 95% of those samples will have a 95% CI that includes the true population mean of 39 years. About 5% of the time, the random sample of 3 individuals will include an unusually young or unusually old set of individuals, and the CI will not overlap the population mean.”

Answer 60

-“A confidence interval (CI) is a statistical estimate of the range of likely values of a parameter in a source population based on the value of that statistic in a study population.”
–“A narrow CI indicates more certainty about the value of the statistic than a wide CI.”
–“When the sample size is small, the sample mean might be quite far from the mean in the total population. ”
-“This is represented by a wide CI that reaches far to the left and right of the sample mean.”
-“When a greater proportion of the total population is sampled for inclusion in the estimation of the mean age, the CI for the mean age will be narrower because there is greater certainty about the sample mean being close to the population mean.”
-“The 95% CI is calculated for each sample based on the number of individuals included in the sample, the mean age of those individuals, and the standard deviation of their ages”
-“If all 20 people in the total population are included in the analysis, no CI is required because the population mean age will be known exactly.”

-“For the top line in Figure 20-2, the sample mean is 34 years, and the CI stretches from 18 to 50 years. Based on this sample, a researcher can be 95% confident that the mean age in the total population is somewhere between 18 and 50 years. If hundreds of random samples of 3 individuals are drawn from the total population of 20, about 95% of those samples will have a 95% CI that includes the true population mean of 39 years. About 5% of the time, the random sample of 3 individuals will include an unusually young or unusually old set of individuals, and the CI will not overlap the population mean.”

Question 61

“20.3 Sample Size Estimation”

-“A sample size calculator/estimator is a tool used to….
-“the range of suggested sample sizes is based on a series of assumptions about the expected characteristics of the sample population.”
-they are available online with no costs
-“When the level of certainty about inputs is low, it is better to err on the side of a larger sample size.”

Answer 61

• identify an appropriate number of participants to recruit for a quantitative study. ”

Question 62

“20.4 Type 1 and Type 2 Errors”

-“Population-based studies aim to have study populations that are representative of their source populations. Sometimes the study population does not capture the true experience of the source population, either because of random chance or because of a study design flaw, such as a sample size that is too small.”
-“an error is a difference between the value obtained from a ___ population and the true value in the ___ population from which the study participants were drawn that occurs by ___ rather than as a result of systematic bias.
-“Bias is a flaw in the way a study was _____ or ____ that leads to an ____result.
-Errors, by contrast, occur ______.

Answer 62

-
-“an error is a difference between the value obtained from a study population and the true value in the larger population from which the study participants were drawn that occurs by chance rather than as a result of system”
-“Bias is a flaw in the way a study was designed or conducted that leads to an inaccurate result. -Errors, by contrast, occur _____

Question 63

-“A type 1(a/ false positive) error occurs when…
-What is an example of a type 1 error?

Answer 63

-a study population yields a statistically significant test result even though a significant difference or association does not actually exist in the source population ”
-a test that shows a patient to have a disease when in fact the patient does not have the disease,

Question 64

-“A type 2 error (b/false negative) occurs when….
-“The best way to minimize the likelihood of type 2 errors is to…

Answer 64

-a statistical test of data from a study population finds no significant result even though a significant difference or association actually exists in the source population.”
-have a large sample size.

Question 65

Summary of Type 1 and Type 2 erroer

Answer 65

Question 66

20.5 Power Estimation
-“power is the ability of a test to detect significant _____ in a population when ____ really do ___.”
-“Power is defined as 1 – β, so a __% likelihood of a type 2 error (that is, β __%) corresponds to a power of __%.
-The standard expectation is that the statistical tests that will be used to answer a study’s main research question should have a power of __% or greater.”
-“The power of statistical tests is ____ when the number of participants included in the analysis is ___.”
-when two ___ or proportions are close to each other then a very ___ sample size is required to detect a significant difference between them
-“When an _____ rate ratio or an odds ratio has a point estimate ___ to 1, a very ___ sample size will be required to yield a CI that is statistically significant and does not overlap 1.”

Answer 66

-“power is the ability of a test to detect significant differences in a population when differences really do exist.”
-“Power is defined as 1 – β, so a 20% likelihood of a type 2 error (that is, β = 20%) corresponds to a power of 80%.
-“The standard expectation is that the statistical tests that will be used to answer a study’s main research question should have a power of 80% or greater.”
-“The power of statistical tests is increased when the number of participants included in the analysis is large.”
-when two means or proportions are close to each other then a very large sample size is required to detect a significant difference between them
–“When an incidence rate ratio or an odds ratio has a point estimate close to 1, a very large sample size will be required to yield a CI that is statistically significant and does not overlap 1.”

Question 67

-“Studies with too __ participants lack adequate power to detect meaningful differences or associations in source populations.”
-“A study that recruits a ___ number of participants will not generate statistically significant test results even when there really is a substantial ___ in the mean survival duration of males and females in a case series or when an exposure in a cohort study is truly a risk factor for the disease outcome of interest in the source population.”
-“If the power estimates for a study are lower than desired, the easiest way to improve the power is to increase the sample size.”

Answer 67

“Studies with too few participants lack adequate power to detect meaningful differences or associations in source populations.”
“A study that recruits a small number of participants will not generate statistically significant test results even when there really is a substantial difference in the mean survival duration of males and females in a case series or when an exposure in a cohort study is truly a risk factor for the disease outcome of interest in the source population.”
-“If the power estimates for a study are lower than desired, the easiest way to improve the power is to increase the sample size.”

Question 68

“20.6 Refining the Study Approach”

-“Initial sample size estimates should be generated ___ in the study design process so that researchers can determine whether they are likely to be able to recruit a sufficient number of participants. Researchers must be prepared to rethink the study approach if their estimated number of available participants will not yield sufficient power.”
-“For example, the intended study design will not work if a researcher expects to be able to recruit about 300 participants but the sample size estimates suggest that 870 participants will be required. In this situation, the study question, the study approach, and/or the source population may need to be modified. A new plan must be crafted that is suitable for the number of participants that the researcher can reasonably expect to recruit.”
-“The sample size estimates generated by sample size and power calculators refer to the ___ population (the actual number of participants), not the ____ population (the number of individuals invited to participate in the study).
-“The number of people sampled for a study needs to be ___ than the ____number of participants, because the participation rate is unlikely to be 100%.”
-“ Suppose that a specialty clinic that has hosted several case–control studies has determined that about half of the patients invited to participate in research studies actually volunteer for them. If a protocol for a new case–control study requires 220 cases to participate in order to have adequate statistical power, the researchers need to be sure that at least 440 cases can be contacted through the clinic. If the clinic does not have an adequately high volume of patients, the study design needs to be revised or other clinics need to be invited to help with recruiting for the study.”

\

Answer 68

–“The sample size estimates generated by sample size and power calculators refer to the study population (the actual number of participants), not the sample population (the number of individuals invited to participate in the study).”
-“The number of people sampled for a study needs to be larger than the required number of participants, because the participation rate is unlikely to be 100%.”

Question 69

“CHAPTER 21
Questionnaire Development”
-“A questionnaire is a….

Answer 69

tool for systematically gathering data from study participants.”

Question 70

“A questionnaire, or survey instrument, is a…

Answer 70

series of questions used as a tool for systematically gathering data from study participants.”

Question 71

What makes a good questionnaire?

Answer 71

-carefully crafted for a specific purpose

Question 72

“Questionnaire design usually works best when it starts with the identification of the ____ and ___ content to be covered by the survey instrument and progresses to choosing the types of ____ and ____ that will be most appropriate for each topic”
-after this is done the wording of the question and the response should be checked carefully
-the sections and questions within those sections should be in logical order
-format of document should be visually appealing and easy to read

Answer 72

“Questionnaire design usually works best when it starts with the identification of the general and specific content to be covered by the survey instrument and progresses to choosing the types of questions and responses that will be most appropriate for each topic”

Question 73

21.2 Questionnaire Content
The first step in designing a questionnaire is to list the ____ that the survey instrument must cover.
-first few questions enables the researcher to ___ that participants meet the _______ criteria for the study.”
-“The remaining questions ask about all of the ____, ______, and ____ (demographic) areas that are the focus of the study question ”
-“Several questions may be required in order to accurately assign participants to key exposure and disease categories”
-“For example, in case–control studies, researchers need to ask questions that allow them to confirm that all cases meet the case definition and that all controls meet the control definition.”
-“When the case or control definition lists multiple inclusion and exclusion criteria, each component of the definition may be evaluated using a separate question.”

-“Prospective cohort studies examining rates of incident disease require a series of questions about both exposure status and disease status. The answers to these questions must allow each participant to be classified as exposed or unexposed, and they must provide evidence that no participant had the disease of interest at the start of the observation period. This may also require a series of questions about various aspects of exposure and disease histories.”
-“A thorough search of the literature for studies related to the research question will help with the identification of the range of additional topics that should be included in the questionnaire.”

Answer 73

-The first step in designing a questionnaire is to list the topics that the survey instrument must cover.
-first few questions enables the researcher to confirm that participants meet the eligibility criteria for the study.”
-“The remaining questions ask about all of the exposure, disease, and population (demographic) areas that are the focus of the study question ”

Question 74

Define Systems thinking…
-what type of questions would stem from this
give an example

Answer 74

-“ is the process of identifying the underlying causes of complex problems so that sustainable solutions can be developed and implemented.”
-“include questions about the various factors that might influence the relationships between key exposures and outcomes.”
-“For example, adults who smoke tobacco products may be more likely than other adults to consume large volumes of alcohol.”“In a study of the relationship between smoking and liver disease, alcohol consumption could be a potential confounder. ”“Because smokers are more likely than nonsmokers to drink, tobacco users may appear to be at a greater risk of liver disease than nonsmokers, even if the rate of liver disease is the same in smokers who drink as it is in nonsmokers who drink. Asking questions about both tobacco use and alcohol use enables the researcher to statistically adjust for different levels of alcohol use by smokers and nonsmokers and thus to more accurately examine the possible relationship between smoking and liver disease.”

Question 75

“Theoretical frameworks can….

Answer 75

inform the diversity of questions that may be relevant to include in the survey instrument.”

Question 76

Agent

Answer 76

“An agent is a pathogen or a chemical or physical cause of disease or injury.
-Infectious agents differ in how contagious, pathogenic, or virulent they are and whether they are drug resistant.
-Drugs and other chemical agents vary in how toxic or addictive they are. ”

Question 77

Host

Answer 77

“A host is a human (or animal) who is susceptible to an infection or another type of disease or injury.
Host factors describe the intrinsic characteristics that influence an individual’s vulnerability to an agent.
People may have different risks of exposure, illness, and adverse outcomes as a result of age, genetics, immunology, comorbidities, nutritional status, health behaviors, psychological factors, and other characteristics.”

Question 78

Environment

Answer 78

“The environment includes the external factors that facilitate or inhibit health.
This construct may refer to physical characteristics of the natural and built environment, such as water quality, air quality, climate, extreme weather events, noisiness, occupational hazards, or proximity to recreational areas, major roads, and various types of healthcare services.
The environment can also refer to the social and political context in which health and disease occur. ”
-“Researchers seeking to understand the causes of an epidemic should gather data about all of the AHE components they think might have contributed to the event. While some agent characteristics must be determined through laboratory testing, data about many of the host and environmental factors can be collected from patients and controls using a survey instrument.”

Question 79

Types of questions:
give examples

Answer 79

“Each survey item should be assigned a specific question type, such as a date question or a yes/no question.”

Question 80

Closed-ended questions
cons?
what are the formats of questions?

Answer 80

“allow a limited number of possible responses.”
-easier to statistically analyze
-cons: may force individuals to choose an answer that really doesn’t match their true opinion
-date and time questions (used to calculate the duration of time between events)..numeric(q needs to be specific w units) and categorical questions->(which can have as few as two response options{dichotomous responses=yes/no) can have also have dozen of possible answers

Question 81

Open-ended questions/ Free response questions
cons?
when are they most useful?

Answer 81

“allow an unlimited number of possible responses.”
-harder to statistically analyze relative to closed end questions
-“ to give multiple answers, and to provide responses not anticipated by the researchers.”
-cons: take long to ask and answer, may result in irrelevant responses
-most useful when they capture initial impressions or clarify responses to close-ended questions

Question 82

Categorical variables can be ranked____ or unordered____

Answer 82

-ordinal, nominal

Question 83

ordinal

Answer 83

-have inherent order
ex, education lvl
“For example, an ordinal question should not allow response of only “less than half” and “more than half,” because that would not allow a response of “exactly half” to be recorded.”

Question 84

nominal

Answer 84

-no built-in order (ranked)
-like occupation
-“For nominal questions, it may be helpful to include an “Other” category that allows respondents to fill in their own answers if none of the listed responses is applicable. (Typically this means asking two questions rather than one. If the response to the main closed-ended question is “Other,” the participant is asked to record a response to a second question that is open-ended.) ”
-“For ranked questions, the researcher chooses how many entries to include on the scale and whether there will be a neutral option.”
“A Likert scale presents ordered “responses to a questionnaire item that asks participants to rank preferences numerically, such as by using a scale for which 1 indicates strong disagreement and 5 indicates strong agreement. Most scales with a neutral option list 5 to 7 categories. Most scales without a neutral option list 4 or 6 categories.”

Question 85

“When multiple responses to a single categorical question might be true for a participant, it may be better to ask…..

Answer 85

a series of yes/no questions rather than asking respondents to “check all that apply.”

Question 86

“For self-report survey items, the researcher must decide whether to add a category for “not applicable” or “I do not know.” Some questions must be answered by all participants because they are essential for determining eligibility for the study.”

“If participants record an answer they are not sure about because they feel they must choose one of the response options, those unreliable responses might cause systematic inaccuracies in the data.”

“information bias may occur if participants who do not know the answer to this question systematically default to providing the answer they assume the researcher wants to hear, such as reporting that they have had their blood sugar checked within the past year even if they are not sure that this test occurred at their last annual checkup. Allowing participants to record responses like “no opinion,” prevent information bias from happening

Answer 86

need an i do not know category to avoid information bias(individuals choosing an answer that they think the research team would like to hear even if they have are unsure about the question.

Question 87

21.5 Anonymity
Anonymity

Answer 87

“is the inability of a participant’s identity to be discerned from his or her responses to a survey instrument or records in a database.
Anonymity protects participants and allows them to provide honest answers to sensitive questions.”

-if they ask for too much info that might be too personal…this can lead to question skipping, dropping out of study, instead of asking for specific birth date, they can ask give them a range of age

Question 88

“21.6 Wording of Questions

Figure 21-5 lists examples of problems with the wording of questions that should be avoided, including ones related to language, content, and responses. After drafting the questionnaire, check each question for clarity and confirm that the responses are also carefully worded. For example:”

Answer 88

Does each question ask what it is intended to ask?
Is the language of each question clear and neutral?
Will members of the study population understand the language?
Do questions about sensitive topics use language acceptable to the source population?
Are the response options clearly presented?
For scaled questions, is the rank order clear? (For example, is it obvious that 1 is“strongly disagree” and 5 is “strongly agree”? Or, alternatively, that 1 is “excellent” and 7 is “poor”?)
For questions with unranked categories, is the order of possible responses alphabetical or otherwise neutral?”

Question 89

questionnaire problems to avoid

Answer 89

Question 90

“21.7 Order of Questions

Many questionnaires start with easy or at least general questions before moving to more difficult or sensitive questions. The questions should be in an order that flows naturally from one topic to another.
It is often best to group similar questions with similar response types, so that they are asked consecutively. However, sometimes it is better to mix up such questions to prevent habituation.”

What is habituation?
How can they avoid this from occuring?

Answer 90

-“Habituation is an error that occurs when participants completing a questionnaire or interview become so accustomed to giving a particular response (like “agree . . . agree . . . agree . . .”) that they continue to reply with the same response even when that does not match their true perspectives.”
-“Survey developers must carefully consider how previous questions could taint the answers to later ones. For example, once a participant has considered a variety of opinions about a topic, he or she can no longer provide an unbiased first impression “the researcher may want to order questions about impressions this way:”

“
First, an open-ended question to garner an initial impression from participants: “What do you do most often when _____?”
Second, a series of yes/no questions to clarify beliefs, perceptions, and practices: “Do you ever _____?”
Last, a concluding open-ended question to allow participants to express final impressions: “Now that you have considered the possibilities, what would you say you do most often when ______?”

Question 91

“21.8 Layout and Formatting”
-make orgnized, easy to read, easy to record answers on
-“Both paper-based and electronic survey pages should be carefully checked for grammatical errors, misspellings, missing questions, gaps in logic, unclear instructions, formatting errors, layout, spacing, and other organizational issues. If the questionnaire appears to be too long, it may be helpful to identify less important questions and remove them at this stage.”
-What are white spaces, for paper based surveys?
-What should be present for internet based surveys?

Answer 91

-“When a paper-based survey (sometimes called a paper-and-pencil survey) is used, the pages should not be too crowded. White space is the blank areas between printed content on a page. White space is helpful for separating sections and making the pages visually appealing. ”
-“When an Internet-based or computer-based survey is used, there must be a high level of contrast between the colors selected for backgrounds and text.”
for both…font should be large and readable

Question 92

“Using multiple pages is advantageous when….

Answer 92

there are many questions in the survey instrument, when some questions will be irrelevant to some participants, and when the researcher wants to require participants to provide an answer to one or more questions before the next set of questions is revealed.”

Question 93

“A filter question or contingency question is…

Answer 93

one that determines whether the respondent is eligible to answer a subsequent question or set of questions.”
“For example, participants who indicate that they have never used tobacco products can be prompted to skip a series of questions about smoking habits.”
“For paper-based forms, instructions for skips must be carefully described in words. ”

Question 94

“In a computer-based survey, skip logic codes can….

Answer 94

automatically hide irrelevant questions from participants based on their responses to filter questions. (In some data collection programs, skip logic is called routing or branching.)”

Question 95

“The layout of the data collection form will vary depending on the mechanism of data collection used. For self-response surveys in which participants record their own answers, a cover letter or list of instructions should explain how answers should be recorded, such as:”

Answer 95

“
“Fill in the oval in front of your answer completely using blue or black ink.”
“Write your answer in block capital letters, as shown in the example below.”
“Select the one answer that best describes you.”
“Circle all options that apply to you.”
“If you answered ‘NO’ to Question 4, then skip to Question 8. If you answered ‘YES’ to Question 4, then please answer Questions 5, 6, and 7 before moving on to Question 8.”
”

Question 96

“21.9 Reliability and Validity”

Question 97

“ Reliability, or precision, is demonstrated when…

Answer 97

consistent answers are given to similar questions and when an assessment yields the same outcome when repeated several times.”
“Agreement between two or more evaluations is another facet of reliability.”

Question 98

“The validity, or accuracy, of a survey instrument (or a diagnostic test or other assessment tool) is

Answer 98

established when the responses or measurements are shown to be correct. ”

Question 99

Reliability/precision and Validity/Accuracy relationship

Answer 99

Question 100

“One aspect of reliability is internal consistency, which is present when….

Answer 100

the items in a survey instrument measure various aspects of the same concept. Some survey instruments ask the same question several different ways, or ask a series of similar questions, in order to confirm the stability of participants’ responses.”
ex, including two questions that are opposite to one another
-if they get both questions right it means that it is reliable and they are not just bs

Question 101

“internal consistency can be confirmed with tests of intercorrelation such as Cronbach’s alpha and the KR-20.Intercorrelation is present when…

Answer 101

two or more related items in a survey instrument measure various aspects of the same concept.”

Question 102

Cronbach’s alpha

Answer 102

“ is a measure of internal consistency that is used with variables that have ordered responses.”
-expressed as numbers 0-1 (near 1 high reliability)

Question 103

“The Kuder-Richardson Formula 20 (KR-20)

Answer 103

is a measure of internal consistency that is used with binary variables.”
-expressed as numbers 0-1

Question 104

“Tests of intercorrelation that examine the reliability of survey instruments are not the same as tests of correlation that compare two or more independent variables.”

Answer 104

interesting

Question 105

Test–retest reliability

Answer 105

“is demonstrated when people who take a baseline assessment and then retake the test later have about the same scores each time they are tested”

Question 106

“Interobserver agreement, or inter-rater agreement,”

Answer 106

“describes the degree of concordance among independent raters assessing the same study participants.”

Question 107

“The kappa statistic, also called Cohen’s kappa and represented with the Greek letter κ, determines ”

Answer 107

“whether two assessors who evaluated the same study participants agreed more often than is expected by chance ”

“For example, the value of the kappa statistic can indicate whether two radiologists examining the same set of x-ray images reach the same conclusion about the presence or absence of a fracture more or less often than expected. If the two radiologists agree as often as expected, κ = 0. If they agree on the interpretation of 100% of the x-ray images shown to both ofthem, κ = 1. If they agree more often than expected, kappa will have a positive value somewhere between 0 and 1. Although complete agreement is rare, a valid study will have a value of kappa that is close to 1.”

Question 108

“Some researchers use the word ____ to describe a theory informed by observations
- use the term _____ to describe a theory informed from more complex abstractions. ”

Answer 108

concept(also general abstraction, construct(multidimensional concept that has been carefully designed for research purposes (ex, trust and leadership are more difficult to quantify)

Question 109

“Content validity/logical validity, is present when..

Answer 109

subject-matter experts agree that a set of survey items captures the most relevant information about the study domain.
Content validity requires consideration of the technical quality of the survey items as well as their representativeness of all the dimensions of the theoretical construct being measured by the survey instrument.”

Question 110

“Face validity

Answer 110

is present when content experts and users agree that a survey instrument will be easy for study participants to understand and correctly complete.”

Question 111

“Some statistical methods can provide information about which items in an assessment tool might be redundant or unnecessary and therefore can be removed without compromising the validity of the survey instrument. For example, ______ _____ ____creates one or more index variables (called components) from a larger set of measured variables. The index variable is generated from the linear combination of measured variables, so it is a weighted average of the contributing variables. The __process determines the optimal number of components, the best measured variables to combine, and the best weights to use for the calculation.”

Answer 111

principal component analysis (PCA)
PCA

Question 112

“Construct validity is present when…

Answer 112

a set of questions in a survey instrument measures the theoretical construct the tool is intended to assess. Construct validity requires the development of an explicit theoretical construct and a rigorous examination of how well an assessment tool represents that construct. Ideally, empirical tests can be used as part of the examination of construct validity. Various measures of correlation are often used for the process of examining interrelationships among variables measuring different aspects of the same theme.”

Question 113

“Factor analysis uses….

Answer 113

measured variables to model a latent variable that represents a construct that cannot be directly measured with one question but appears to have a causal relationship with a set of measured variables.”

Question 114

Convergent validity

Answer 114

“is present when two items that the underlying theory says should be related are shown to be correlated.”

Question 115

“ Discriminant validity is present when..

Answer 115

two items that the construct says should not be related are shown not to be associated.”

Question 116

“Criterion validity/concrete validity, uses…

Answer 116

an established test or outcome as a standard (or criterion) for confirming the utility of a new test that examines a similar theoretical construct. For example, a new test of intelligence can be validated against standard IQ tests, and a shorter version of a widely used assessment tool can be validated against the longer original version. ”

Question 117

“There are two main approaches to examining criterion/concrete validity.”
“Concurrent validity….
“Predictive validity…

Answer 117

-Concurrent validity is evaluated when participants in a pilot study complete both the existing and new tests and the correlation between the test results is calculated. A strong correlation between the tests is evidence that the new test is valid.”
-ex,Concurrent validity could be demonstrated by comparing scores on the new test with scores on the MCAT, which is the current standard test for medical college admission in the United States.

-Predictive validity is appraised when the new test is correlated with subsequent measures of performance in related domains. Suppose researchers create a new test intended to predict success in medical school.
ex, administering the test to incoming medical students and comparing their results on the new test with their performance on the initial licensing exam (USMLE Step 1) taken 2 years later.”

Question 118

What is one way to improve validity?

Answer 118

“include survey questions or modules that are identical to the ones used in previous research projects. ”
“new research projects usually require the development and testing of a completely new survey instrument.”
“However, several widely used and validated tests are available to researchers, ”

Question 119

“health-related quality of life”

Answer 119

“a multidimensional construct that captures an individual’s perceived physical, mental, emotional, and social well-being and the perceived impact of health status on the quality of daily life”

Question 120

“21.11 Translation

Translation of the survey instrument into one or more additional languages may be necessary if the source population contains speakers of more than one language. (Translation may also be required when an ethics review committee requires materials to be presented in the committee’s preferred language as well as in the language of the source population.) Researchers using multiple languages must be certain that the translated version expresses the same meaning as the original survey. Accuracy may require the rephrasing of whole sentences, not just direct word-for-word translations.”

Question 121

“One way to ensure that the correct meaning is being conveyed is to use back translation, or double translation, in which

Answer 121

one person translates the questionnaire from the original language to a new language and then a second person translates the survey instrument in the new language back into the original language.”
-“A comparison of the original version of the survey with the back-translated version will reveal where the second-language “translation does not match the intended meaning of the original version.

A second approach is to have two translators independently translate the survey instrument from the original to the new language. The two translations are compared, and a consensus process is used to decide which words and phrases best convey the precise meaning and complexity of the original questionnaire.”

Question 122

“A pilot test/ pretest, is a

Answer 122

small-scale preliminary study conducted to evaluate the feasibility of a full-scale research project.
A pilot test of a questionnaire is helpful for checking, among other issues:”
“
The wording and clarity of the questions
The order of the questions
The ability and willingness of participants to answer the questions
The responses given, and whether the responses match the intended types of responses
The amount of time it takes to complete the survey”
“The researcher should ask several volunteers to help with the pilot test. These volunteers should be from the target population and meet the eligibility criteria for the study (in terms of age, exposure and disease status, and other key factors), but they should not be members of the sample population. They should be asked to complete the preliminary survey and then provide feedback about content, clarity, layout, timing, and other factors. Feedback may be provided individually or as part of a focus group. The survey instrument is revised based on these observations. Several rounds of pilot testing may be required to develop a sound survey instrument.”