• Explain the steps of the scientific method
• Define theory and hypothesis
• Discuss research ethics

Steps of the Scientific Method

The basic steps in the scientific method are explained below:

• Observe a natural phenomenon and define a question about it. Perhaps you notice that senior students at your school seem happier than the younger students. You turn this into the question: Who is happier—first-year or senior students?
• Make a hypothesis, or potential solution to the question.

• Test the hypothesis. You do this by designing a study and collecting data (you could do this using a variety of methods such as a survey, or experiment). To test this hypothesis, you could conduct a study in which you survey both first-year and senior students about their levels of happiness and compare the results. There are, of course, several problems with this. People might lie about their happiness, might not be able to accurately report on their own happiness, or might not use the numerical scale in the same way. Note that with these limitations in mind, modern psychologists employ a wide range of methods to assess happiness. They use, for instance, “peer report measures” in which they ask close friends and family members about the happiness of a target individual. Researchers can then compare these ratings to the self-report ratings and check for discrepancies. Modern psychologists also use biological measures such as saliva cortisol samples (cortisol is a stress-related hormone) or fMRI images of brain activation (the left pre-frontal cortex is one area of brain activity associated with good moods). Additionally, the parameters of the study would need to be clearly identified—all first-year and senior students? What ages, and what colleges? Once you clearly identified the parameters of your study and determined how to measure happiness, you could conduct the study.
• Analyze the data. If the hypothesis is true, find more evidence or find counter-evidence. If the hypothesis is false, create a new hypothesis or try again. Here you may find that your hypothesis was supported and the senior students reported higher levels of happiness than first-year students. You would report on the data that you found and run statistical analysis to show the differences in happiness levels between the groups.
• Draw conclusions and repeat—the scientific method is never-ending, and no result is ever considered perfect. From this study, you may conclude that the senior students are happier, and you may even give explanations as to why—is it because they have stronger social support networks or a better idea of what they want to focus on? You could then design a study to examine those aspects of college life to see, for example, if there is a correlation between social support networks and happiness levels.

This video explains how Psychology follows the scientific method to draw conclusions about human behavior.

You can view the transcript for “Is Psychology a Science?” here (opens in new window).

Theories and Hypotheses

Watch this video to understand the difference between a theory and a hypothesis:

You can view the transcript for “Hypothesis vs theory – Intro to Psychology” here (opens in new window).

The knowledge generated from research is organized according to scientific theories. A scientific theory is a comprehensive framework for making sense of evidence regarding a particular phenomenon. When scientists talk about a theory, they mean something different from how the term is used in everyday conversation. In common usage, a theory is an educated guess—as in, “I have a theory about which team will make the playoffs,” or, “I have a theory about why my sister is always running late for appointments.” Both of these beliefs are liable to be heavily influenced by many untrustworthy factors, such as personal opinions and memory biases. A scientific theory, however, enjoys support from many research studies, collectively providing evidence, including, but not limited to, that which has falsified competing explanations. A key component of good theories is that they describe, explain, and predict in a way that can be empirically tested and potentially falsified.

A hypothesis is a specific prediction based on previous research or scientific theory. For example, based on the accepted theory that exercise is good for your health, a researcher might hypothesize that exercising a few hours before an exam will improve test scores.

Scientific research should also be verifiable, predictable, falsifiable, and fair:

1. Verifiability: An example of verifiability in scientific research is a study on the effectiveness of a new drug for treating a certain medical condition. To achieve verifiability, the researchers must clearly document their methods and explain how they administered the drug to the study participants and measured its effects. Other researchers should be able to replicate the study using the same methods to see if they get the same results.
2. Predictability: An example of predictability in a scientific theory is the theory of evolution by natural selection. This theory allows us to make predictions about the characteristics of species and how they may change over time in response to different environmental conditions. For example, the theory predicts that species that are well-adapted to their environment will be more likely to survive and reproduce, leading to the spread of their traits through the population.
3. Falsifiability: An example of falsifiability in scientific research is a study on the effects of a new type of diet on weight loss. The hypothesis being tested is that the diet will lead to significant weight loss compared to a control group. To test this hypothesis, the researchers could design an experiment in which some participants follow the diet and others do not, and measure the difference in weight loss between the two groups. If the results show that the diet does not lead to significant weight loss, the hypothesis is falsified.
4. Fairness: An example of fairness in scientific research is a study on the relationship between exercise and heart health. To ensure fairness, the researchers must consider all of the data collected, including any data that may contradict their hypothesis. For example, if the hypothesis is that exercise leads to improved heart health, the researchers cannot ignore data showing that some participants had no improvement or even experienced negative effects on their heart health after exercising. All of the data must be accounted for and considered when evaluating the hypothesis.

Research Ethics

Watch this video to learn about ethics in research:

You can view the transcript for “Ethics in research – Intro to Psychology” here (opens in new window).

Psychologists follow a series of guidelines and receive prior approval from institutional research boards before beginning experiments. Among the most important principles are the following:

1. Informed consent: In general, people should know when they are involved in research, and understand what will happen to them during the study (at least in general terms that do not give away the hypothesis). They are then given the choice to participate, along with the freedom to withdraw from the study at any time. Still, it’s important to note that certain kinds of methods—such as naturalistic observation in public spaces, or archival research based on public records—do not require obtaining informed consent.
2. Privacy: Although it is permissible to observe people’s actions in public—even without them knowing—researchers cannot violate their privacy by observing them in restrooms or other private spaces without their knowledge and consent. Researchers also may not identify individual participants in their research reports (we typically report only group means and other statistics). With online data collection becoming increasingly popular, researchers also have to be mindful that they follow local data privacy laws, collect only the data that they really need (e.g., avoiding including unnecessary questions in surveys), strictly restrict access to the raw data, and have a plan in place to securely destroy the data after it is no longer needed.
3. Risks and Benefits: People who participate in psychological studies should be exposed to risk only if they fully understand the risks and only if the likely benefits clearly outweigh those risks.
4. Deception: Social psychologists sometimes need to deceive participants (e.g., using a cover story) to prevent participants from modifying their behavior in unnatural ways, especially in laboratory or field experiments. Deception is typically only permitted (a) when the benefits of the study outweigh the risks, (b) participants are not reasonably expected to be harmed, (c) the research question cannot be answered without the use of deception, and (d) participants are informed about the deception as soon as possible, usually through debriefing.
5. Debriefing: This is the process of informing research participants as soon as possible of the purpose of the study, revealing any deceptions, and correcting any misconceptions they might have as a result of participating. Debriefing also involves minimizing harm that might have occurred. For example, an experiment examining the effects of sad moods on charitable behavior might involve inducing a sad mood in participants by having them think sad thoughts, watch a sad video, or listen to sad music. Debriefing would therefore be the time to return participants’ moods to normal by having them think happy thoughts, watch a happy video, or listen to happy music.