Step 3: Conduct the Study Flashcards
What are the basic steps to Step 3: Conduct the Study?
- Obtain ethical approval
- Recruit sample
- Collect data
Why might a pilot study or pilot interview be conducted?
Identifies potential problems and strategies to modify the research plan
What are the primary methods of sampling for quantitative research?
MEMORY: Clearly Quantitative Provides Measurable Conclusions
C - Convenience
Q - Quota
P - Purposive
M - Matching
C - Consecutive
What are the primary methods of sampling for qualitative research?
MEMORY: Cleverly Tells Personal Stories
C - Convenience
T - Theoretical
P - Purposive
S - Snowball/network
What is the population in a research study?
- Well-defined set that has certain properties
- Can be people, animals, objects, substances and/or events
What is the eligibility criteria in a research study?
- Population descriptors used to select subjects from the sample
o Examples include age, marital status, diagnoses, comorbidities, etc. - Referred to as inclusion/exclusion criteria
- Used to restrict the population to a homogenous group
- Increases accuracy of study findings
What is the target population in a research study?
- The entire set of individuals or elements who meet the eligibility criteria
- Who we are attempting to generalize the findings to
What is the accessible population in a research study?
- The portion of the target population to which the researcher has access
What is the sampling frame in a research study?
- The resource you can access the population
What is the sample in a research study?
- Those participating in the study
You are attempting to determine if in Canada, a persons GPA affects their satisfaction with their university experience.
To rule out their relationship status and home life affecting the results, you decide to only talk to university students 18-25 years old that are single and living in the dorms.
Because you are a student at MacEwan, you ask other students at MacEwan to obtain you needed information.
In this study, what group would all university students in Canada make up?
Population
You are attempting to determine if in Canada, a persons GPA affects their satisfaction with their university experience.
To rule out their relationship status and home life affecting the results, you decide to only talk to university students 18-25 years old that are single and living in the dorms.
Because you are a student at MacEwan, you ask other students at MacEwan to obtain you needed information.
In this study, what are the requirements of being 18-25 years old, single, and living in the dormitories considered?
Eligibility criteria
You are attempting to determine if in Canada, a persons GPA affects their satisfaction with their university experience.
To rule out their relationship status and home life affecting the results, you decide to only talk to university students 18-25 years old that are single and living in the dorms.
Because you are a student at MacEwan, you ask other students at MacEwan to obtain you needed information.
In this study, what group would make up all Canadian university students that are 18-25, single, and living in dormitories?
Target population
You are attempting to determine if in Canada, a persons GPA affects their satisfaction with their university experience.
To rule out their relationship status and home life affecting the results, you decide to only talk to university students 18-25 years old that are single and living in the dorms.
Because you are a student at MacEwan, you ask other students at MacEwan to obtain you needed information.
In this study, what group would all of the university students at MacEwan make up?
Accessible population
You are attempting to determine if in Canada, a persons GPA affects their satisfaction with their university experience.
To rule out their relationship status and home life affecting the results, you decide to only talk to university students 18-25 years old that are single and living in the dorms.
Because you are a student at MacEwan, you ask other students at MacEwan to obtain you needed information.
In this study, you use Meskanas in order to email all the students at MacEwan to ask them to participate in the study. What is Meskanas in this study?
Sampling frame
You are attempting to determine if in Canada, a persons GPA affects their satisfaction with their university experience.
To rule out their relationship status and home life affecting the results, you decide to only talk to university students 18-25 years old that are single and living in the dorms.
Because you are a student at MacEwan, you ask other students at MacEwan to obtain you needed information.
In this study, what group would make up the 50 people that meet the above criteria and consented to be part of the study?
Sample
What is the population descriptors used to select subjects from the sample in order to restrict the population to a homogenous group?
Eligibility criteria
What is the complete set group of individuals that have a common characteristic that is going to be studied?
Population
What is the entire set of individuals that meet the eligibility criteria?
Target population
What is the portion of the target population are available for the researcher to contact?
Accessible population
What is the resource a researcher can used to determine a sample?
Sampling frame
Can be as simple as a list of all the people
What is the group of people that are participating in the study?
Sample
What is the sample size?
The number of participants in the final sample
What is the key determinant of sample quality in qualitative research?
Adequacy of the sample size
What is a type II sampling error?
How is it prevented?
o Failure to reject null hypothesis and demonstrate significance in a statistical test
o Prevented by having a larger sample size
What is a basic rule to ensure that a quantitative sample size is large enough?
At least 30 participants for each variable in the study
What is a power analysis? How does it help determine the sample size of a quantitative research study?
Statistical calculation that includes
* Power level – an indicator of the probability of avoiding a type II error
* Level of significance – probability of occurrence happening by coincidence rather than design
* Effect size – strength of relationship between the variables (Strong relationship needs a smaller sample to demonstrate its existence)
* Sample size – determined once all other factors are set and determines the minimum number of participants required
What type of methodology requires smaller sample sizes that are based on informational needs?
qualitative research
What are some factors that should be considered in the qualitative research sample size?
Richness and depth of information being gathered
Lack may be due to a sample size that is too small
Data saturation
No new themes of phenomena are emerging
Aspiration, not an achievable outcome
Can be affected by data quality
Why might a qualitative research study lack richness and depth of the information that was gathered?
Sample size that is too small
What is data saturation?
No new themes of phenomena are emerging
Aspiration, not an achievable outcome
Can be affected by data quality
What is a representative sample?
What study type is this important?
How is it achieved?
A sample whose key characteristics closely approximate those of the population
Quantitative research
More easily achieved with
o Random selection
o Random assignment to groups (randomization)
What influences the sample size of a quantitative research study?
Increased control decreases the sample size
Degree of precision, which depends on reliable and valid instruments
Study design
Control over treatment
Control group
Sampling procedure and cost
How is the sample size of a quantitative research design generally determined?
Power analysis
What is another term for probability sampling?
Random sampling
Describe simple random sampling
A type of probability sampling
Uses a sampling frame – a list of all population elements
Examples:
Put all names in a jar
Use a number table
Use a number generator
As sample size increases, representatives increases
Involves random selection of elements from the sampling frame
Cumbersome
Not used in large, national surveys
You are attempting to determine if in Canada, a persons GPA affects their satisfaction with their university experience.
To rule out their relationship status and home life affecting the results, you decide to only talk to university students 18-25 years old that are single and living in the dorms.
Because you are a student at MacEwan, you ask other students at MacEwan to obtain you needed information.
You determine that 793 people meet your requirements but you only need 50 for your study design. You decide to put everyone’s name in a jar and then draw them out to determine who you talk to. What is this sampling called?
Simple random sampling
A type of probability sampling
You are attempting to determine if in Canada, a persons GPA affects their satisfaction with their university experience.
To rule out their relationship status and home life affecting the results, you decide to only talk to university students 18-25 years old that are single and living in the dorms.
Because you are a student at MacEwan, you ask other students at MacEwan to obtain you needed information.
You determine that 3% of the population have a 4.0 GPA, 40% are between 3.0-3.99, 43% are between 2.0-2.99, and 10% are between 1.0-1.99, and 4% are below 0.99 GPA.
You decide to ensure that your sample reflects these percentages. What type of sampling is this?
Stratified random sampling
A type of probability sampling
Define stratified random sampling
- Population is first divided into two or more strata, then select elements randomly from each subgroup
- Enhances representativeness
- Can sample proportionately or disproportionately from the strata
Define cluster/multistage sampling
A type of probability sampling
Successive random sampling of units from larger to smaller units
o i.e. provinces, then postal codes, then households
Widely used in national surveys
Larger sampling error than in simple random sampling, but more efficient
Used when population is large or spread over a wide geographic area
Define systematic sampling
A type of probability sampling
Selection of every nth case from the available population using a random starting point
o i.e. selecting every 10th person on a patient list until desired sample size reached
Sample interval
o Standard distance between the selected elements
Define convenience sampling
A type of nonprobability sampling
- May also be called an accidental sample
- Use of the most conveniently available people
- Most widely used approach by quantitative researchers
- Most vulnerable to sampling biases
- Weakest form of sampling but most used method
Define quota sampling
A type of nonprobability sampling
Convenience sampling within specified strata of the population
Researcher will need to know the different strata that make up the population
Enhances representativeness of sample
o Ensures representation by certain groups
o i.e. % of men and % of women to match larger population
Define matching sampling
A type of nonprobability sampling
* Used to obtain equivalent groups
* Subjects are matched on some characteristic that could affect the DV
o i.e. gender, age, income bracket, etc.
Define consecutive sampling
A type of nonprobability sampling
* A first come, first serve idea
* Involves taking all of the people from an accessible population who meet the eligibility criteria over a specific time interval, or for a specified sample size
* A strong non-probability approach for “rolling enrollment” type accessible populations
* Risk of bias low unless there are seasonal or temporal fluctuations
Define purposive sampling
A type of nonprobability sampling
* Also called purposeful or judgmental
* Sample members are hand-picked by researcher to achieve certain goals because they have extensive knowledge/experience of the phenomena
* Used more often by qualitative than quantitative researchers
* Can be used in quantitative studies to select experts or to achieve other goals
May be based on typical cases, extremes, maximum variation, criterion, or by using confirming/disconfirming cases
What is maximum variation sampling in purposive sampling?
o Deliberately selecting cases with a wide range of variation on dimensions of interest
What is extreme case sampling in purposive sampling?
o Also called deviant case sampling
o Select cases from most unusual or extreme informants
What is typical case sampling in purposive sampling?
o Average or typical cases
What is criterion sampling in purposive sampling?
o Cases who meet a predetermined criterion of importance
What type of sampling is used towards the end of data collection when using purposive sampling during a study?
Confirming/disconfirming cases
What are confirming cases in purposive sampling?
What are disconfirming cases in purposive sampling?
When are these used?
Confirming cases fit researcher’s conceptualizations, therefore increase credibility
Disconfirming cases are new cases that do not fit; therefore, challenge researcher interpretations
Used towards the end of data collection
Define theoretical sampling
A type of nonprobability sampling
* Used in grounded theory
* Selects participants who can add to theory development
* Helps researcher decide where to find data for optimal development of theory
* Based on findings that are emerging from the data