Types of studies
A group we want information about
What is a population?
Allows every member of a population to have an equal chance of being selected
What is a simple random sample
Producing inaccurate information that systematically favors one outcome over other outcomes
What is bias
explanatory variable in an experiment
What is a factor
Part of the population we examine to gain information about the whole population
What is a sample?
A rule is used to select a sample
What is a systematic random sample
Over- or under-represent a portion of the population
Coverage Bias
Various groups that factors take
What is a level
A value that describes a sample
What is a statistic?
Divide the population into homogeneous groups called strata
What is a Stratified random sample
participants cannot be contacted or refuse to participate
What is Non-response bias
The combinations of levels from all the factors that an experimental unit receives
What is a treatment
A value that describes a population
What is a parameter?
Divides the population into random groups called clusters
What is a Cluster random sample
Respondents underestimate or exaggerate
What is response bias
A group that is treated the same way as the treatment groups but does not receive the treatment
What is a control group
Respondents write comments, essays, and other free response text
What is an open sample survey?
A combination of Stratified and cluster sampling, usually used with larger populations
What is a multi-stage sample
Unconscious or automatic
What is hidden bias
Experimental unit receives both the treatment and the control
What is a Matched pairs design