Comparison group
Control group
Knowledge level continuum
Mortality
Classical experimental design
Cross-sectional survey design
Instrumentation error
Independent variable
History
Cohort study
Testing effects
Trend study
O
Experimental group (O1) (X) (O2) Control group (O1) (O2)
A threat to internal validity that refers to the weaknesses of a measuring instrument itself, such as invalidity, unreliability, improper administration, or mechanical breakdown
This kind of research design takes different samples of people who share a similar characteristic at different points in time
A threat to internal validity that refers to the principle that take pretests will affect posttest scores
This kind of research design takes place when research participants have a certain condition and/or receive a particular treatment and are sampled over time
A threat to internal validity that refers to the loss of research participants through normal attrition over time in research designs that required pretests and posttests
The range of knowledge levels, from exploratory to descriptive to explanatory, at which all research questions can be answered
A threat to internal validity that refers to events not accounted for in the research designs that may alter the second and subsequent measurements of the dependent variable
A nonexperimental group to which research participants have not been randomly assigned for purposes of comparison with the experimental group; not to be confused with control group
A variable that is not dependent on another variable but is believed to cause or determine changes in the dependent variable
A group of randomly assigned research participants in a study who do not receive the experimental treatment and are used for comparison purposes; not to be confused with comparison group
