Unit 8 Populations and Samples

What is a Sample? Sample = small subset of a population. Populations are the things that possess specific attributes – they can be people, objects, events, or elements. Data collected from samples are used to make generalizations about the overall population

Commonly Used Terms You should know the definitions for the following terms: Target population Generalization Inclusion and exclusion criteria Representativeness Attrition

Quantitative Research Quantitative Randomization the goal – probability sampling ideal Large populations - power analysis Effect size Threats to validity – nonprobability sampling Ability to make generalizations may be an issue

Qualitative Research Qualitative purposeful/purposeful sample Research participants hand-picked Threats to validity Researcher bias

Important Considerations Sample and sampling method clearly identified Probability or non-probability method used? Inclusion criteria Sample size Response rate