Stats Unit 3 Vocab Test

population

the entire group of individuals we want information about.

census

collects data from every individual in the population.

sample

subset of individuals in the population from which we collect data.

sample survey

study that collects data from a sample to learn about the population from which the sample was selected.

Random sampling (SRS)

involves using a chance process to determine which members of a population are chosen for the sample.

observational study

observes individuals and measures variables of interest, but does not attempt to influence the responses. hard to establish cause + effect relationships

retrospective

observational studies that examine existing data for a sample of individuals

prospective

observational studies that track individuals into the future

experiment

deliberately imposes treatments on experimental units to measure their responses. can establish cause+effect relationships

cluster

a concentration of data values on a graph, a group of similar data points in analysis, or a natural subdivision of a population in sampling

bias

a systematic error that causes data or estimates to consistently deviate away from the true population value

Undercoverage

a type of selection and coverage error that happens when a part of the target population has no chance—or a reduced chance—of being included in the sample frame