What are the Similarities and Differences Between Causal-Comparative and Correlational Research Methods?
Causal-comparative and correlational methods (as defined in educational research textbooks) are similar in that both are nonexperimental methods because they lack manipulation of an independent variable which is under the control of the experimenter and random assignment of participants is not possible. This means, among other things, that the variables must be observed as they occur naturalistically. As a result, the key and omnipresent problem in nonexperimental research is that an observed relationship between an independent variable and a dependent variable may be spurious. That is, the relationship is not a causal relationship; it is a relationship that is the result of the operation of a third variable (see Figure 1). For an example of the third variable problem, note that self-reported “gender role identification” and high school “algebra performance” may be related. However, that relationship would probably largely be due to the joint influence of the third variable of “gender-