You have read at several places in this volume how important it is to select a dependent variable or an outcome measure with a great deal of care. It is the link between all the hard preparation and thinking you have done and the actual behavior you want to measure. Even if you have a terrific idea for a research project and your hypothesis is right on target, a poorly chosen dependent variable will result in disaster.The following nine items are important to remember when selecting such a variable. Use the following as a checklist when you search through previous studies to find what you need.
What follows is more about selecting dependent variables (or screening measures for assignment to groups as independent variables). At best, with all things going in your favor, it is difficult to find exactly the test you want to use to diagnose, evaluate, determine effects, use as a placement tool, and so on. The dependent variable you select may not even be a test in the formal sense of the word. But if it is, you need to be concerned about many different characteristics and qualities of the instrument.With that in mind, the following outline of criteria will help you compare and contrast various tests. For each test you want to consider, complete the outline to the extent possible and then use this information to make a decision. Be sure to weigh each of the criteria accordingly. For example, although a test might be appropriate as far as its design and purpose, if it is prohibitively expensive or requires special training (which you do not have) to administer it, it is not likely that you will be able to use it.