- Explain the steps of the scientific method
- Define theory and hypothesis
- Discuss research ethics
Psychology relies on the scientific method to study behavior and mental processes. In contrast to other methods that people use to understand the behavior of others, such as intuition or personal experience, the hallmark of scientific research is that there is evidence to support a claim. Scientific knowledge is empirical: it is grounded in objective, tangible evidence that can be observed time and time again, regardless of who is observing.
Process of Scientific Research
The scientific method involves taking ideas (in the form of theories and hypotheses) and testing those against the real world (in the form of empirical observations).
In order to ask an important question that may improve our understanding of the world, a researcher must first observe natural occurrences. By making observations, a researcher can define a useful question. After finding a question to answer, the researcher can then make a prediction (a hypothesis) about what they think the answer will be. This prediction is usually a statement about the relationship between two or more variables. After making a hypothesis, the researcher will then design an experiment to test their hypothesis and evaluate the data gathered. These data will either support or refute the hypothesis. Based on the conclusions drawn from the data, the researcher will then find more evidence to support the hypothesis, look for counter-evidence to further strengthen the hypothesis, revise the hypothesis and create a new experiment, or continue to incorporate the information gathered to answer the research question.
The Scientific Method
The basic steps in the scientific method are:
- Observe a natural phenomenon.
- Ask a question.
- Make a hypothesis, or potential solution to the question.
- Design a study and collect data to test your hypothesis (this could be done using a variety of methods such as a survey or experiment).
- 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.
- Draw conclusions and repeat—the scientific method is never-ending, and no result is ever considered perfect.
Imagine a researcher wanting to examine the hypothesis that caffeine enhances memory. She knows there are several published studies that suggest this might be the case, and she wants to further explore the possibility. She designs an experiment to test this hypothesis. She randomly assigns some participants a cup of fully caffeinated tea and some a cup of herbal tea. All the participants are instructed to drink up, study a list of words, then complete a memory test.
There are three possible outcomes:
- The caffeine group performs better (support for the hypothesis).
- The no-caffeine group performs better (evidence against the hypothesis).
- There is no difference in the performance between the two groups (also evidence against the hypothesis).
Let’s look at how the researcher should interpret each of these three possibilities.
First, if the results of the memory test reveal that the caffeine group performs better, then this supports the hypothesis. It appears, at least in this case, that caffeine is associated with better memory. This does not, however, prove that caffeine causes better memory. There are still many questions left unanswered. How long does the memory boost last? Does caffeine work the same way with people of all ages? Is there a difference in memory performance between people who drink caffeine regularly and those who never drink it? Could the results be a random occurrence? Because of these uncertainties, we do not say that a study—especially a single study—proves a hypothesis. Instead, we say the results of the study offer evidence in support of the hypothesis.
The second possible result from the caffeine-memory study is that the group who had no caffeine demonstrates better memory. This result is the opposite of what the researcher expects to find. Here, the researcher must admit the evidence does not support her hypothesis. She must be careful, however, not to extend that interpretation to other claims (finding increased memory in the no-caffeine group would not be evidence that caffeine harms memory).
Also, since prior studies suggested that caffeine helps memory, this researcher’s single study alone does not prove that all the others were wrong—perhaps the earlier research studied participants of different ages or who had different baseline levels of caffeine intake. This new study simply becomes a piece of fabric in the overall quilt of studies of the caffeine-memory relationship. It does not, on its own, definitively falsify the hypothesis.
Finally, it’s possible that the results show no difference in memory between the two groups. In this case, the researcher once again has to admit that she has not found support for her hypothesis.
Why the Scientific Method Is Important for Psychology
The scientific method allows psychological data to be replicated and confirmed in many instances, under different circumstances, and by a variety of researchers. Through replication of experiments, new generations of psychologists can reduce errors and broaden the applicability of theories. It also allows theories to be tested and validated instead of simply being conjectures that could never be verified or falsified. All of this allows psychologists to gain a stronger understanding of how the human mind works.