1.8 Psychologists Use the Scientific Method

Step 1: Formulate a Theory Psychologists study research questions that they find interesting. When they encounter a puzzling question about how people think, feel, or act, they seek to understand that process. To answer your question about the best study techniques, you will need to know the study methods that students use and how effective they are. You will also need to formulate a theory (Figure 1.17, Step 1). A theory is an explanation of how some mental process or behavior occurs. The theory consists of interconnected ideas or concepts that explain prior research findings and make predictions about future events.

To formulate your theory, you need to learn about prior research related to the topic. You should start by performing a literature review in which you explore the scientific articles related to your ideas. Many resources are available to assist with literature reviews, including Google Scholar (https://scholar.google.com/), the American Psychological Association’s PsycInfo (https://www.apa.org/pubs/databases/psycinfo), and a government database called PubMed (https://pubmed.ncbi.nlm.nih.gov/). You can search these databases by asking questions related to your research question, such as “How do students prefer to study?” Or you might search keywords and phrases related to the topic, such as “repeated practice.” The results of your searches will reveal whether other scientists have already investigated similar topics.

The findings of prior research will help you refine your theory and guide the direction of your study. A clearly stated theory is important because it is the basis for Step 2 of the scientific method. In this case, let’s use information from this chapter and state your theory as “Students learn better by repeated practice than by rereading information.”

Step 2: Develop a Testable Hypothesis Once you have a theory, you need to state your hypothesis, which is a specific, testable prediction about what should be observed if the theory is accurate (Figure 1.17, Step 2). Any one theory is usually tested by several separate hypotheses across different studies. Every hypothesis tests an aspect of the theory by targeting one of the four goals of science listed above: describing, predicting, controlling, and explaining.

For example, your research may have the goal of simply describing something, such as what study techniques students use or what techniques they think are best. Or your goal may be to predict a relationship between two things, such as exam scores based on how much time students spend using certain study methods. As another possibility, your goal may be to control factors that affect an outcome, such as students’ study methods, to explain which form of studying yields higher exam scores. Each of these different goals will lead you to develop a different testable hypothesis that is specific to that goal. For example, a good hypothesis for the goal of controlling students’ studying to explain which study technique leads to better outcomes might be “Students will perform better on an exam after repeated practice with information than they will after repeated reading of the information.”

Step 3: Test With a Research Method After you have stated a clear hypothesis, you move to the third step in the scientific method, in which you choose the research method to test your hypothesis (Figure 1.17, Step 3). The three main types of research methods you can use are descriptive, correlational, and experimental (Figure 1.18), which are explained in detail later in this chapter.

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The first box is types of research methods with 3 boxes coming out of it. The boxes are, Descriptive methods: Describe what is occurring (Example: What study techniques do students believe are best?), Correlational methods: Test the relationship between variables (Example: What is the relationship between how much time students spend using certain study methods and their later exam scores?), and Experimental methods: Investigate what causes an outcome (Example: Which study technique results in the best exam scores possible?). There are three boxes coming from descriptive methods, which are observational studies (allow researcher to watch what participants do in a natural environment or a laboratory), self-reports (use surveys, questionnaires, or interviews to gather information directly from participants), and case studies (allow in-depth investigation of one or a few people or an organization.

The most appropriate research method depends on the goal of your research and your hypothesis. For example, if your goal and hypothesis are related to describing something, such as which study techniques students think are best, then you should use descriptive methods (see Figure 1.18, orange boxes). However, if the goal and hypothesis refer to predicting a relationship between two things, such as how much time students spend using certain study techniques and their exam scores, then you should use the correlational method (see Figure 1.18, blue box). If your goal and hypothesis are about controlling what causes an outcome, such as how study techniques affect exam scores, then you need to use the experimental method (see Figure 1.18, green box). The research method you use also depends on how much control you need over manipulating and measuring certain factors in the study. Each factor, called a variable, is something in the world that can vary and that the researcher can manipulate (change), measure (evaluate), or both. You will learn about two types of variables in study unit 1.11.

Let’s look at the variables for your experiment. There is a variable you will manipulate and a variable you will measure. Your hypothesis indicates that you will manipulate the variable of what study technique students use. Half of your participants will engage in repeated reading, in which they read a passage and then reread it two more times before they take an exam on the material. The other half of your participants will read the material and repeatedly practice with it on two practice tests before taking an exam on the material. To determine whether there is a cause/effect relationship between the study technique and exam scores, you must try to control for other factors, such as the students’ academic abilities. To do so, you randomly assign each student to use one of the study techniques. Doing so will help ensure that students’ overall grade point average (GPA) is similar in each group and that neither group has better students. In your experiment, the variable that you measure is the participants’ performance on a later exam. A difference in exam scores across participants who used different study techniques will suggest whether one study technique was more effective than the other.

Step 4: Analyze the Data In Step 4 of the scientific method you analyze the data from your research to see whether the results support your hypothesis (Figure 1.17, Step 4). First you summarize the raw data. Then you mathematically determine whether differences really exist between the different sets of summarized data. Both of these forms of data analysis are described in Appendix A. In our example, you could summarize your data by comparing performance to see which group scored higher on the exam: students who repeatedly read or repeatedly practiced. Next, you must decide whether any differences between these conditions were meaningful. That is, you must decide whether they are a result of the factor of interest: study technique. In other words, you must determine whether you found a significant effect. In this case, you might find a significant effect if the exam scores of the students who repeatedly practiced are higher than the exam scores of those who repeatedly read the passage. This result would suggest that repeated practice is a better study method in general.

Unfortunately, some psychologists alter their hypothesis based on their data analysis. This practice is highly discouraged because it is easy to come up with explanations for data after the fact, but there is little confidence that your explanation is correct because the research was not designed to explore this new explanation. For these reasons, researchers should document their hypotheses and methods before they start collecting and analyzing data (Lindsay, 2017; Vazire, 2018).

Step 5: Share the Results and Conduct More Research As the last step in the scientific method, you must report the research results (Figure 1.17, Step 5). Sometimes researchers will have assessed many aspects of the phenomena they investigated. In that case, it is important that they report all of the data and interpretations, not just the results that are consistent with their hypothesis. Reporting all the data increases confidence in the research and the results (Morling & Calin-Jageman, 2020). Unethically reporting only the data that support a hypothesis is called cherry-picking.

Some researchers report their results at a scientific conference where attendees present their findings at talk or poster sessions. You may have seen a psychology poster session at your own school or at a psychology conference (Figure 1.19). Another way to report research results is to publish them in a peer-reviewed scientific journal. Published articles are a more thorough means of presenting findings because they include all the background for the research, the full research methodology, the complete data analyses, and a discussion of what the results mean in relation to other research on the topic. Publishing articles is a great way to make your psychological research accessible to many people.

Sometimes the best way to verify the results of a study is to conduct the same study again, a process called replication. If other psychologists repeat the same procedures with similar research participants, they should expect to obtain the same general results. Replication is an important part of the scientific method. It means that research is ongoing, and additional results from scientific studies increase our confidence in the findings (Goodman et al., 2016; Vazire, 2018). Thanks to replication, the five steps in the scientific method are a continuous cycle (see Figure 1.17). Indeed, recently some psychologists have reported being unable to replicate previous research findings (Collaboration, 2015; Maxwell et al., 2015; Shrout & Rodgers, 2018). These attempts are important because they continue to provide evidence related to psychological theories. To help with future attempts at replication, researchers need to be transparent about all aspects of their research. Best practices include reporting specific details of all the methods and analyses that were used (Vazire, 2018). In addition, researchers are encouraged to provide free access to the materials they used and to share the data they collected so that others can replicate their analyses (Morling & Calin-Jageman, 2020).

Finally, as part of the cycle of the scientific method, you and other researchers should also determine what issues related to the topic need additional investigation. No single study definitively answers any research question. A study shows only what happened in a particular set of circumstances with specific participants. For example, if you conduct your research study with undergraduate students at a college in Illinois, would you get the same results with other students of diverse identities at colleges in other parts of the United States? And will your results apply to students who attend college in other countries? Conducting additional research to extend the findings to new situations and diverse participants will increase confidence in the results’ importance and generalizability. When the results or conclusions from many studies are the same, the findings are more likely to be trustworthy. In fact, as described earlier in the chapter, a variety of research has indeed found that repeated practice truly is a more effective way to study and learn than repeated reading of information (see Dunlosky et al., 2013). Are you now inspired to use this information to change how you study to use the effective technique of repeated practice?