Chapter 2. The Methods of Psychology

Topic: Does SAT Performance Correlate to Family Income and Education Level?

Statistical Concepts Covered:

As you’ve read in this chapter on scientific methods, psychologists often perform experiments, where they manipulate one variable, the independent variable, and measure its effect on another variable, the dependent variable. This approach is powerful because it allows the researcher to make claims about causal relationships. However, some questions either cannot or should not be answered through experimental manipulation. In these cases, the researchers may collect data on two variables without manipulating anything, and then look to see if there is a systematic relationship, or correlation, between those variables.

This applet uses data that was collected from The College Board’s 2013 College-Bound Seniors Total Group Profile Report, which includes information about SAT scores as well as demographic and academic measures for tens of thousands of students who took the SATs as well as information about previous years’ scores. The textbook states that evidence requires two key critical thinking skills: 1) that we interpret the data without bias; and 2) that we look for not just the truth, but the whole truth, in the evidence. Keep that in mind as you explore these data and learn about the strengths and weaknesses of correlational designs.