Ninth Edition CoverGraziano & Raulin
Research Methods (9th edition)

Chapter 9 Essay Questions
Controls to Reduce Threats to Validity

  1. What effects would general control procedures have on each of the different types of validity (statistical, construct, internal, and external)?

  2. Confounding variables are primarily a threat to internal validity. How might confounding variables also threaten the other types of validity?

  3. What types of validity are affected by using replication as a control procedure? How does replication improve each type of validity?

  4. Distinguish between single- and double-blind procedures. How does each control for subject and experimenter effects?

  5. Using objective measures is often considered an effective control for many types of subject and experimenter effects. Explain how objective measures provide this control. If objective measurement is not possible, what other techniques also provide control over subject and experimenter effects?

  6. How can the use of deception provide control in a research setting? How are confounding effects controlled by deception?

  7. Distinguish between the concepts of participant selection and participant assignment. How does each provide control that reduces threats to validity? What types of validity are protected by each technique?

  8. Distinguish between free random assignment, randomizing within blocks, matched random assignment, and some of the other available matching procedures.

  9. What aspect of random assignment makes it such a powerful control procedure?

  10. What is an experiment? How do the characteristics of an experiment reduce threats to validity?

  11. What is meant by general control procedures?

  12. What ethical issues arise when deception is used in research? How are the participants protected in such cases?

  13. Explain this statement: “Confounding variables can threaten both internal validity and construct validity.”

  14. How is replication a control procedure?

  15. Why is it important to use objective measures in research?

  16. How can deception in an experiment be ethically justified?

  17. Why is random assignment of participants to conditions an important control procedure?

  18. How is matching participants a control?

  19. Why is internal validity of such importance in experimentation?

  20. Why is it important in experimentation for experimental and control groups to be equivalent at the start of a study?

  21. A researcher selects 30 children from among the 473 enrolled in an elementary school. On completion of the study, the researcher wants to discuss the results in terms of all elementary school children. Identify the various populations and samples involved in this study. What cautions must the researcher be aware of in generalizing the results?

  22. If you were the teaching assistant for this course, how would you explain to students the concept of representativeness of a sample?