Three Flashcards
(9 cards)
What is boundary setting
action of precess of determining and enacting selection criteria for study participants, study concepts or study phenomena
What are guidelines for determining inclusion/exclusion criteria?
- Appropriateness - the extent to which the inclusion/exclusion criteria fit the overall purpose of the study – determined by research design, problem, purpose and structure
- Adequacy - the extent to which the inclusion/exclusion criteria yields sufficient data to answer the research problem
Saturation of data - qualitative
Sample size calculation - quanitative
What are the steps of sampling in quantitative studies?
- Define population
- develop sampling plan
- determine sample size
- implement sampling procedures
- compare critical values of sample to population
What is probability sampling?
based on probability theory:
- parameters of population are known
- every member or element has equal probability of being selected
**Preferred for quantitative studies, higher external validity, can be impractical
What are probability sampling examples?
- SIMPLE RANDOM SAMPLING: ex. drawing from a hat
- SYSTEMATIC SAMPLING: determining a sampling interval width based on the needed sample size, then selecting every ___ element from a sampling frame
- STRATIFIED RANDOM SAMPLING:
- CLUSTER SAMPLING
What is non-probability sampling?
sample is not chosen on the basis of equal chance to be selected from a population
**used when not feasible to develop a sampling frame, easier to conduct
What are non-probability sampling examples?
- CONVENIENCE SAMPLING - involvement of available subjects
- PURPOSIVE SAMPLING - deliberate selection of individuals by researcher on the basis of predefined criteria
- SNOWBALL SAMPLING - asking subjects to provide access to others who may meet the criteria
- QUOTA SAMPLING
What are ways to set boundaries in qualitative studies?
- geographical location/physical setting
- cultural group
- personal experience
What are strategies for sampling?
- Maximum variation: seeking individuals who are extremely different along dimensions that are the focus of the study
- Homogenous selection: choosing participants w/similar experiences
- Theory based selection: choosing participants who exemplify a particular theoretical construct
- Confirming or disconfirming cases: finding informants who will either support or challenge the emerging theory
- Extreme case: select case that represents an extreme example of the phenomenon
- Typical case: typical cases that characterize a phenomenon