Threats to Internal Validity
The threat is out of the researcher's control and can only occur before or during the study, not after to impact the study's results.
What is history (or threat of history)?
Occurs when multiple treatments are given at the same time and thus interfere with one another's results.
What is multiple-treatment interference?
A type of research design that is considered longitudinal due to repetitive observations.
What are time-series research designs?
The threat where the participants age out of the study.
What is maturation?
Occurs when a study is conducted in a lab setting, but the results are not equal to what is observed in the natural environment.
What are lab settings/bias (or what is the Hawthorne effect)?
When there is a control group along with the experimental group.
What is a control series research design?
Occurs when a pretest is the same as the posttest in questions.
When the treatments of an experiment are repeated unnecessarily.
What are irrelevant replicability of treatments?
A threshold is placed after the pretest to determine where participants are placed. (i.e., if a participant scores above 5 on a scale they will be placed in the control group.)
What is regressional discontinuity?
When certain participants are selected to be in the study by the researcher.
What is selection bias?
Occurs when the participants are nonrandomly assigned and certain groups react differently to the experimental variables.
What is selection and experimental treatment bias?
Considered the goal of what an experimental design should achieve.
What is a true experiment?
Occurs when outliers in the group's statistics are not regulated and skew the data.
What are regressional artifacts?
When extra components in a measure are unnecessary and have an impact on the results.
What are irrelevant responsiveness of measures?
Bonus (not in the article): a type of time-series analysis that has two experimental groups both have pre-and post-tests, however the independent variable is introduced at different times.
What is a switching replication time-series experiment?