Experiment - At least one independent variable is manipulated.
Experimental Design - the structure by which variables are positioned or arranged in an experiment.
Experimental Validity Threats
Internal
History
Maturation
Testing
Instrumentation
Statistical regression
Selection
Mortality |
External
Interaction effect of testing
Interaction of selection and treatment
Reactive effects of arrangements
Multiple treatment interference |
Construct
Inadequate explication
Mono-operation bias
Mono-method bias
Hypothesis guessing
Confounding constructs with levels |
Statistical Conclusion
Low statistical power
Violated assumptions
Fishing and error rate
Reliability of measures
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Experimental designs
Posttest-only control group design
Pretest-posttest control group design
Solomon four-group design
Factorial designs
Repeated measures designs |
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Random assignment for internal validity
Random selection for external validity