Research Design Explained--Chapter 1 Summary

Chapter 1 Very brief chapter overview

The first part of this chapter tells you why psychology is a science. The second part shows you some of the pitfalls of blindly applying methods from other sciences to psychology (pay close attention the problems of internal, external, and construct validity, as well as ethical issues--you'll see these issues again and again!). The third part explains how you will benefit from being able to understand and conduct research.

Chapter Summary

Mitchell and Jolley explain that psychology is a science because, like other sciences, psychology:

produces objective evidence that can be replicated (indeed, replicated with the same success as physics experiments are replicated)
unearths observable, objective evidence that either supports or refutes existing beliefs
creates new knowledge
is open-minded about claims, even those that go against common sense
is skeptical about ideas that, even though they make sense, have not been supported by any research evidence.

Next, Mitchell and Jolley take a closer look at the problems of using the scientific method to understand behavior. At one level, there are two basic problems about doing research to get answers to questions about human behavior.

The study you do may be unethical.
The study you do may not answer the question.

At another level, there is only one problem: Is the study ethical?
According to APA's ethical principles (which every researcher should consult before doing a study), a study is ethical if the potential benefits of the study outweigh the study's potential for harm. Thus, there are two ways to increase the chances that your study is ethical.

First, reduce the potential for harm. Following the ten tips in table 1.3 (pg 23) can help reduce the potential for harm.
Second, make your study worth doing. This means:

Having an interesting, important research question; and
Collecting data that will allow you to answer that question.

Mitchell and Jolley address point 1(developing an interesting, important research question) in Chapter 2. But what about point 2 (collecting data that will allow you to answer your research question)? Obviously, your study should have validity. But what type of validity? The type of validity you will need will depend on your research question.

If your research question is about whether something causes a certain effect, your study must have internal validity. As you'll see later, only experimental designs have internal validity. Thus, if you want to make cause-effect statements, you should do an experiment.

Alternatively, if your research question is about what percentage of a population do some behavior, you need a study that has external validity. One key to having external validity is to obtain a large, random sample of participants from that population. Studying such a representative sample helps you to generalize your results to the larger population.

Finally, if your research question involves measuring or manipulating some state of mind (hunger, stress, fear, motivation, love, etc.), then you need construct validity. As you'll see in Chapter 3, achieving construct validity is not easy.

Depending on the research question, you may be interested in only one of these kinds of validity. Sometimes, you may want to have two of these kinds of validity. Rarely, however, will you need--or be able to conduct--a study that has all three types of validity.

The last part of the chapter (pages 26-32) explains how you will benefit from studying research methods. Thus, by the end of the chapter, you should be able to cite eight reasons for mastering material in the text (to review these reasons, see table 1.6).

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