How to Design and Evaluate Research in Education

388 PART 4 Quantitative Research Methodologies www.mhhe.com/fraenkel7eASSOCIATIONS BETWEEN CATEGORICAL VARIABLESBoth crossbreak tables and contingency coefficients can be used to investigate possibleassociations between categorical variables, although predictions from crossbreaktables are not precise. Fortunately, there are relatively few questions of interestin education that involve two categorical variables.For Discussion1. Suppose a researcher was interested in finding out what factors cause delinquentbehavior in teenagers. What might be a suitable comparison group for the researcherto use in investigating this question?2. Could observation be used in a causal-comparative study? If so, how?3. When, if ever, might a researcher prefer to conduct a causal-comparative studyrather than an experimental study? Suggest an example.4. What sorts of questions might lend themselves better to causal-comparative researchthan to experimental research? Why?5. Which do you think would be easier to conduct, causal-comparative or experimentalresearch? Why?6. Is random assignment possible in causal-comparative research? What about randomselection? Explain.7. Suppose a researcher was interested in the effects of team teaching on student attitudestoward history. Could such a topic be studied by means of causal-comparativeresearch? If so, how?8. What sorts of variables might it be wise for a researcher to think about controlling forin a causal-comparative study? What sorts of variables, if any, might be irrelevant?9. Might a researcher ever study the same variables in an experimental study that he orshe studied in a causal-comparative study? If so, why?10. We state in the text that, in general, quantitative variables should not be collapsedinto categorical variables because (a) the decision to do so is almost always an arbitraryone and (b) too much information is lost by doing so. Can you suggest anyquantitative variables that, for these reasons, should not be collapsed into categoricalvariables? Can you suggest some quantitative variables that could justifiably betreated as categorical variables?11. Suppose a researcher reports a higher incidence of childhood sexual abuse in adultwomen who have eating disorders than in a comparison group of women withouteating disorders. Which variable is more likely to be the cause of the other? Whatother variables could be alternative or contributing causes?12. Are there any research questions that cannot be studied by the causal-comparativemethod?13. A professor at a private women’s college wishes to assess the degree of alienationpresent in undergraduates as compared to graduate students at her institution. Shewill use an instrument that she has developed.a. Which method, causal-comparative or experimental, would you recommend sheuse in her inquiry? Why?b. Would the fact that the researcher plans to use an instrument that she herselfdeveloped make any difference in your recommendation?Note1. The interested reader is referred to J. D. Elashoff (1969). Analysis of covariance: A delicate instrument.American Educational Research Journal, 6: 383–399.