PSYC 2300 Lecture Notes - Lecture 9: Pyramid Scheme
Document Summary
Selecting research participants: large group including all potential subjects, may be defined in many ways, target population. Sample: small subgroup of subjects chosen from population, may need to define a subpopulation. Generalization: apply results from sample to population, depends on how representative the sample is. Everyone in population has equal chance of participating. Ensures enough participants to ensure validity and no more. Simple random sampling: every member of population has an equal and independent chance of being selected, sampling with replacement vs sampling without replacement. Systematic: every kth element is sampled. Stratified random: population divided into strata, random sample from each strata, representative sample. Proportionate random: proportions of strata in the population is same as the proportion in the sample. Cluster: large populations, sampling in at group unit, groups = randomly selected. Multistage: identify clusters, randomly sample cluster, sample individuals from sample, non-probability sampling. Assume sample looks like population, hard to show bias. Difficult to establish response rates: establishing validity.
