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

Chapter 8 Essay Questions
Hypothesis Testing, Validity,
and Threats to Validity

  1. What must a researcher do before he or she can legitimately accept a causal hypothesis? Explain how the researcher would accomplish this task.

  2. Diagram the process of how a research idea becomes a specific research hypothesis. Explain each of the steps, using examples where necessary.

  3. Explain how a single research idea, expressed as a statement of the problem, can actually be translated into several different research hypotheses. Develop an example of your own (different from the examples in the book) that illustrates this process.

  4. Define each of the various types of validity, and describe how each might be threatened in a research study.

  5. For each of the confounding variables discussed in Chapter 8 (maturation, history, testing, instrumentation, regression to the mean, selection, attrition, and diffusion of treatment), define what is meant by the confounding variable, and give at least one example of how such a variable might affect the results of a study.

  6. Distinguish between subject and experimenter effects. What do the two have in common? What are the implications of each for the interpretation of research findings?

  7. Distinguish between statistical and practical significance.

  8. Explain this statement: "Theory is crucial in developing a research hypothesis."

  9. "The research hypothesis actually encompasses three hypotheses." Explain this statement; identify and define the three hypotheses, their function, and their importance.

  10. How do we deal with the confounding-variable hypothesis?

  11. Explain why it is so important in experimental research to rule out confounding-variable hypotheses.

  12. What are the major types of validity in research?

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

  14. What is meant by subject and experimenter effects? How do they threaten the validity of a study? Give several examples.

  15. Explain, as if to another student in the course, how replication can be achieved in the process of varying the operational definitions when developing research hypotheses from problem statements. Give examples.

  16. Explain how, because of ethical constraints, it is nearly impossible to obtain a truly random sample of human participants in research.

  17. How is external validity affected by ethical constraints?