Chapter 7: Estimating the frequency of behaviors and beliefs Flashcards
population
the entire set of people a researcher is interested in
census
a set of observations that includes all members of the population of interest
biased (unrepresentative) sample
some members of the population of interest have a much higher probability than other members of being included in the sample
unbiased (representative) sample
all members of the population have an equal and known chance of being included in the sample
ways a sample could be biased
- researchers might only study those who they can contact conveniently
- researchers might only study those who volunteer to respond
convenience sampling
a biased sampling technique in which researchers choose a sample based on those who are easiest to access and are readily available
self-selection
a from of sampling bias that occurs when a sample contains only participants who volunteer to participate
probability (random) sampling
every member of the population of interest has an equal and known chance of being selected for the sample
simple random sampling
the most basic form of probability sampling in which the sample is chosen completely randomly from the population of interest
systematic sampling
a probability sampling technique in which the researcher uses a randomly chosen number N and counts for every Nth member of a population to achieve a sample
cluster sampling
a probability sampling technique in which clusters of participants within the population of interest are selected at random, followed by data collection from all individuals in each cluster
multistage sample
a probability sampling technique involving at least 2 stages: a random sample of clusters, followed by a random sample of people within the selected clusters
stratified random sampling
a form of probability sampling in which the researcher identifies particular demographic categories or strata, and then randomly selects individuals within each category, proportionate to their assumed membership in the population
oversampling
a form of probability sampling, a variation of stratified random sampling in which the researcher intentionally overrepresents one or more groups
random assignment
researchers randomly assign participants to different experimental groups