Research Appraisal - Eppp Knowledge

1. Which option best defines ecological validity when judging whether findings generalize to real-world conditions?

   Degree procedures and setting approximate real-life conditions. Evaluates how closely the experimental context mirrors natural settings, enhancing the relevance of findings to everyday applications.

2. Identify the design type: participants are randomly assigned to IV levels and DV is measured.

   True experimental design. Involves random assignment and independent variable manipulation, providing the strongest basis for causal inferences in research.

3. Which sampling method best supports generalizability from sample to population?

   Probability (random) sampling from the target population. Enables statistical inference by ensuring every population member has an equal selection chance, minimizing sampling bias.

4. Which external validity threat occurs when pretesting changes participants' responsiveness to the treatment?

   Pretest sensitization (interaction of testing × treatment). Arises when initial testing alters treatment responsiveness, limiting applicability to populations without prior measurement exposure.

5. Which internal validity threat is most consistent with differential dropout between conditions?

   Attrition (experimental mortality). Results from uneven participant loss across groups, potentially creating non-equivalent samples and biased outcomes.

6. Which internal validity threat occurs when the measurement instrument or rater calibration changes over time?

   Instrumentation. Stems from shifts in measurement tools, criteria, or observer reliability across assessments, introducing systematic bias.

7. Which internal validity threat is most consistent with change caused by an external event during the study?

   History. Refers to extraneous events between measurements that could influence the dependent variable, confounding treatment effects.

8. What is the key design feature that most strongly supports causal inference?

   Random assignment to conditions. Equates groups on potential confounders, enabling causal attribution of dependent variable differences to the independent variable manipulation.

9. Which design feature best reduces selection bias in quasi-experiments when randomization is not feasible?

   Matching or statistical control (for baseline covariates). Adjusts for pre-existing differences by pairing similar participants or using covariates, improving group comparability.

10. Which internal validity threat occurs when repeated testing itself changes subsequent test performance?

    Testing (practice or sensitization effects). Involves changes in performance due to familiarity, learning, or reactivity from prior exposure to the measurement.

11. What is the main purpose of a manipulation check in evaluating an experimental study?

    Verify the IV manipulation changed the intended construct. Confirms that the experimental manipulation successfully affected the targeted variable, supporting construct validity of the independent variable.

12. Which internal validity threat occurs when extreme scores move toward the mean on retesting?

    Regression to the mean. Arises from statistical tendencies where extreme initial scores naturally shift toward the average on retesting due to error variance.

13. What is the primary threat to internal validity in a one-group pretest–posttest design?

    History and maturation (cannot be ruled out). Lacks a control group, so external events or natural changes over time could account for pretest-posttest differences.

14. Which option best defines internal validity in research design evaluation?

    Confidence that the IV caused the observed DV change. Ensures that observed effects on the dependent variable are attributable solely to the independent variable, ruling out alternative explanations.

15. Which threat describes a group maturing at a different rate because groups were nonequivalent at baseline?

    Selection × maturation interaction. Occurs in non-equivalent groups where differential growth rates interact with selection, confounding treatment interpretations.

16. Which external validity threat occurs when results depend on the specific participant characteristics sampled?

    Interaction of selection × treatment. Restricts applicability when treatment outcomes vary based on sampled participants' unique traits, not broader populations.

17. Identify the problem: the treatment group receives more therapist contact time than the control group.

    Confound (attention/contact time differs by condition). Introduces an extraneous variable where unequal attention may influence outcomes independently of the specific treatment.

18. Identify the design type: groups differ on an IV without random assignment, then DV is measured.

    Quasi-experimental design. Compares pre-existing groups without randomization, limiting causal claims due to potential selection biases and confounds.

19. Which option best defines a confound when evaluating adequacy of an experimental design?

    A variable that covaries with the IV and affects the DV. Represents an extraneous factor that systematically varies with the independent variable, providing alternative explanations for results.

20. Which internal validity threat is most consistent with improvement due to natural development over time?

    Maturation. Involves internal processes like growth or fatigue that systematically alter participants over time, independent of the treatment.

21. Which external validity threat occurs when results depend on the specific setting or context of the study?

    Interaction of setting × treatment. Limits generalizability when treatment effects are contingent on unique study contexts, not replicating in other environments.

22. Which internal validity threat occurs when initial group differences, not the IV, explain outcomes?

    Selection bias. Arises in non-randomized designs where pre-existing group differences, rather than the treatment, account for outcome variations.

23. Which option best defines external validity when judging generalizability of findings?

    Extent findings generalize across people, settings, times, measures. Assesses how well study results apply to other populations, contexts, periods, or operationalizations beyond the specific experiment.

Study these flashcards