Psychological Research Methods



Psychological research methods involve a series of tasks including formulating hypotheses, defining variables, and selecting a research design. They must also select participants that accurately represent the broader population and take steps to avoid bias. Additionally, psychological researchers use descriptive and inferential statistics to make sense of their data. Psychologists do not draw strong conclusions based on a single study. Instead, they seek to replicate research findings across multiple studies. Some early psychological research was plagued by breaches of ethics. Today, ethical guidelines exist to protect participants' safety and well-being.

At A Glance

  • All research designs require clear operational definitions of the variables being studied. Meaningful research results depend on the reliability and validity of the measures used.
  • Descriptive research includes case studies, naturalistic observation, and survey research.
  • Correlational research provides information about the strength and direction of a relationship between variables. Correlations can predict behavior but do not provide causal information.
  • Experimental designs allow scientists to draw conclusions about causes of events. Experiments require random assignment of participants to an experimental or control condition.
  • Small or biased samples may produce results that do not apply to the general population because the samples do not accurately reflect the population of interest.
  • Experimenter biases may shape study outcomes through intentional or unintentional influences on data collection and analysis.
  • Historically, it has been difficult to publish replication studies and studies that did not show exciting new findings. A growing emphasis on replication has revealed that some established findings may be weaker than originally thought.
  • Descriptive statistics describe a data set. The mean (average), median (middle score), and mode (most common score) are measures of central tendency. Range and standard deviation are measures of variability.
  • Inferential statistics help determine whether it is possible to make predictions about the general population based on research results. In large samples, findings can be statistically significant without representing a large enough effect to have practical significance.
  • Following historical abuses of research participants, researchers must adhere to modern ethical guidelines when working with human and animal participants.
  • Federal regulations require ethics board approval for research studies. Researchers must explain any risks and obtain participants' informed consent.