Ch. 9 Exam 2 Flashcards
A particular group of individuals or elements who are the focus of the research.
Population (Accessible, Target); TOP
an entire set of individuals or elements who meet the sampling criteria.
target population; determined by sampling criteria
the portion of the target population to which the researcher has reasonable access.
accessible population; available to researchers
individual units of the population and sample.
elements; participant, subject, object, or event —> BOTTOM
Defines the selected group of people or elements from which data are collected for a study.
Sample; selected with sampling method
Selection of a subset of a population to represent the whole population. Selecting a group of people, events, behaviors, or other elements with which to conduct a study. Members of the sample can be called the subjects or participants.
Sampling
a listing of every member of the population, using the sampling criteria to define membership in the population. Subjects are selected from the sampling frame.
Sampling frame
outline strategies used to obtain a sample for a study. Probability sampling plans and non-probability sampling plans.
Sampling plan
Characteristics that the subject or element must possess to be part of the target population. Ex: in a study of pts who have dementia, a researcher wishes to examine the effects of moderate exercise on pts abilities to preform self-care. The researcher decides to use subjects between 70 and 80 years of age who have been diagnoses with dementia for less than 1 year.
inclusion criteria
Characteristics that can cause a person or element to be excluded from the target population.
exclusion criteria
A researcher uses a sample whose members have characteristics similar to those of the population from which it is drawn. Mean that the sample, access population, and target population are alike in as many ways as possible.
Representativeness
Extending the findings from the sample under study to the larger population. The extent is influenced by the quality of the study and consistency of the study’s findings.
Generalization
Researchers may narrowly define the sampling -> Researcher may have difficult obtaining an adequately sized sample from the accessible population, which can limit the generalization of findings.
Probability Sampling (Generalizability increases)
A sample in which subjects have a broad range of values being studies, which increased the representativeness of the sample and the ability to generalize from the accessible population to the target population. This sampling method is least likely to produce findings that are generalizable to a large population.
Convenience
Purposeful = judgmental or selective sampling
Theoretical Network —> network or snowball sampling or chain or nominated sampling.
Quota
Non-probability sampling (generalizability decreases)
The expected difference in values that occurs when different subjects from the same sample are examined. Difference is random bc some values will be higher and others lower than the average population values.
random variation
Consequence of selecting subjects whose measurement values differ in some specific way from those of the population. These values DO NOT VARY RANDOMLY around the population mean.
Systematic variation (bias)
What are the 2 ways to define sampling criteria?
homogenous sample
heterogenous sample
Researchers may narrowly define the sampling -> Researcher may have difficult obtaining an adequately sized sample from the accessible population, which can limit the generalization of findings.
homogenous sample
A sample in which subjects have a broad range of values being studies, which increases the representativeness of the sample and the ability to generalize from the accessible population to the target population.
heterogenous sample
% of subjects who declined to participate in the study, 80 subjects approached and 4 refused. 4 divided by 80 = 0.95 = 95% refusal rate.
refusal rate
% of subjects who consented to be in the study. 80 subjects approached and 76 accepted. 76 divided by 80 = 0.95 = 95% acceptance rate.
acceptance rate
withdrawal/drop of loss of subjects from a study. Attrition rate = # of subjects withdrawing divided by # of study subjects x 100. Ex: a researcher begins a study with 250 subjects, and 50 subjects drop out before the study is concluded. What is the attrition rate? 50/250*100 = 20%
sample attrition
of subjects who remain in and complete a study.
sample retention
the side of difference between the groups or the strength of the relationship between 2 variables. Small effect size <0.30 or <-0.30. Medium effect size = 0.30 to 0.50 or <-0.30 to -0.50. Large effect size >0.50 or >-0.50
effect size
descriptive study tends to require a larger sample size than the others. Number of variables, measurement sensitivity, and data analysis techniques.
type of quantitative study conducted
of study data occurs when additional sampling provides no new info.
saturation
