2also called attrition; loss of participants who have enrolled in a study. Can occur for numerous reasons, including voluntary drop-out, relocation, or death
mortality
3a type of testing effect in which the order a test is administered affects the outcome
order effect
4a threat to internal validity caused by the research participant consciously or unconsciously influencing the outcome
participant bias
5the ability of a study to detect a difference or relationship
power
6a type of testing effect in which exposure to the pretest affefcts the outcomes of subsequent testing
practice effect
7also called Rosenthal effect; occurs when the intervention leader's positive expectations for an outcome lead the participants to respond more favorably
pygmalion effect
8when research participants are assigned to groups in such a way that each participant has an equal chance of being assigned to the available groups
random assignment
9a type of sampling in which each potential particpant has an equal chance of being selected for participation in a study
random sampling
10the tendency of individuals who have extreme scores on a measure to regress toward the mean when the measure is re-administered
regression to the mean
11conducting a study that duplicates most or all the features of a previous study
replication
12the number of individuals who respond to a survey divided by the number of individuals who initially received the survey
response rate
13also called Pygmalion effect; occurs when the intervention leader's positive expectations for an outcome lead the participants to respond more favorably
Rosenthal effect
14the degree to which a sample does not represent the intended population
sampling error
15differences in groups that occur due to the selection process
selection threat
16the accuracy of the conclusions drawn from the statistical analysis of a study
statistical conclusion validity
17changes that occur because of the test administration process
testing effects
18in the case of a measure, the ability of that measure to assess what it is intended to measure. In the case of a study, when the conclusions drawn are based on accurate interpretations of the study findings and not confounded by alternative explanations
validity