Quiz Week 11 Flashcards
Population:
Well-defined group with specified characteristics
Sample:
Subset of overall population
Element:
Most basic unit
Convenience sample:
Uses most readily available subjects. Easy and inexpensive. Disadvantage: increased risk of bias.
Snowball sampling:
Type of convenience sampling. Use of original participant’s contacts. For instance drug addicts contacting other drug addicts (no fixed address or normal social ties).
Purposive sampling:
Cases are handpicked. For instance rare genetic disease.
Quota sampling:
Used to access different subgroups of a population. Eg. 10% men, 90% women in order to represent group/population
Simple random sampling
Random number generation to select sample.
Stratified random sampling:
Population divided into homogenous subsets (strata).
Why are eligibility criteria so important?
So as not to skew results. Do they fit criteria? Allows generalizability of your findings.
What is/are the main purpose(s) of sampling?
To be able to draw conclusions about a population.
Name the two major headings under which sampling falls.
Inclusion & exclusion criteria.
What are the advantages of random sampling?
Ease of assembling a sample. Considered representative. Considered fair given equal opportunity to be selected.
What is the aim of stratified random sampling?
To increase representativeness of sample.
Name and briefly describe two other types of probability sampling.
Cluster sampling: geographic areas – area sampling.
Systematic sampling: selection of fixed intervals eg. Every 5th case.
