PSY 510 CASE STUDY FINAL PREPARATION
MANUAL 2026
◉ Internal Validity. Answer: The extent to which an investigation
rules out plausible alternative explanations of the results
◉ Temporal Precedence. Answer: Need to assure that A really does
come before B in the analysis (threat to internal validity)
◉ Selection. Answer: The presence of systematic differences
between groups before an experimental manipulation (threat to
internal validity)
◉ History. Answer: Any event (other than the IV) occurring in or out
of the study that can explain the results (i.e., provides for an
alternative hypothesis) (threat to internal validity)
◉ Maturation. Answer: Processes (within subjects) that change over
time that are unrelated to the study's variables of interest (e.g.,
growing older, wiser, stronger) (threat to internal validity)
, ◉ Regression to the Mean. Answer: Tendency for extreme scores on
a measure to revert or regress toward the distribution mean when it
is re-administered (threat to internal validity)
◉ Attrition. Answer: Significant or differential loss of subjects over
time (threat to internal validity)
◉ Testing. Answer: The effects that taking a test one time can have
on subsequent test performance (threat to internal validity)
◉ Instrumentation. Answer: Changes in the measuring instrument
or measurement procedure over time (threat to internal validity)
◉ External Validity. Answer: The extent to which the results of an
investigation can be generalized beyond the conditions of the study
to other populations, settings, and circumstances
◉ Sample Characteristics. Answer: The degree to which one is able
to generalize from the sample included in a given RCT to other
individuals who vary across certain demographic characteristics
(threat to external validity)
◉ Stimulus Characteristics. Answer: One's ability to generalize
beyond the specific aspects or stimuli of a given investigation (threat
to external validity)
MANUAL 2026
◉ Internal Validity. Answer: The extent to which an investigation
rules out plausible alternative explanations of the results
◉ Temporal Precedence. Answer: Need to assure that A really does
come before B in the analysis (threat to internal validity)
◉ Selection. Answer: The presence of systematic differences
between groups before an experimental manipulation (threat to
internal validity)
◉ History. Answer: Any event (other than the IV) occurring in or out
of the study that can explain the results (i.e., provides for an
alternative hypothesis) (threat to internal validity)
◉ Maturation. Answer: Processes (within subjects) that change over
time that are unrelated to the study's variables of interest (e.g.,
growing older, wiser, stronger) (threat to internal validity)
, ◉ Regression to the Mean. Answer: Tendency for extreme scores on
a measure to revert or regress toward the distribution mean when it
is re-administered (threat to internal validity)
◉ Attrition. Answer: Significant or differential loss of subjects over
time (threat to internal validity)
◉ Testing. Answer: The effects that taking a test one time can have
on subsequent test performance (threat to internal validity)
◉ Instrumentation. Answer: Changes in the measuring instrument
or measurement procedure over time (threat to internal validity)
◉ External Validity. Answer: The extent to which the results of an
investigation can be generalized beyond the conditions of the study
to other populations, settings, and circumstances
◉ Sample Characteristics. Answer: The degree to which one is able
to generalize from the sample included in a given RCT to other
individuals who vary across certain demographic characteristics
(threat to external validity)
◉ Stimulus Characteristics. Answer: One's ability to generalize
beyond the specific aspects or stimuli of a given investigation (threat
to external validity)
