Statistics for People Who (Think They) Hate Statistics

by Neil J. Salkind

and the conclusions you may reach based on those results, are necessarily inconclusive. If you are not sure that the test does what it is supposed to and that it does so consistently without randomness in its scores, how do you know that the nonsignificant results you got aren’t a function of the lousy test tools rather than an actual reflection of reality? Want a clean test of your hypothesis? Make reliability and validity an important part of your research. You may have noticed a new term at the beginning of this chapter—dependent variable. In an experiment, this is the outcome variable, or what the researcher looks at to see whether any change has occurred as a function of the treatment that has taken place. And guess what? The treatment has a name as well—the independent variable. For example, if a researcher examined the effect of different reading programs on comprehension, the independent variable would be the reading program, and the dependent or outcome variable would be reading comprehension score. The term dependent variable is used for the outcome variable because the hypothesis suggests that it depends on, or is affected by, the independent variable. Although these terms will not be used often throughout the remainder of this book, you should have some familiarity with them.