What are the major types of psychological research methods?

The major types of psychological research methods encompass a range of approaches that facilitate the understanding of behavior and mental processes. The classification into descriptive, correlational, and experimental research is particularly significant.

Descriptive research involves methods that provide a snapshot of the variables at play without manipulation. This includes various techniques such as surveys and observational studies, offering insights into "what" phenomena exist and identifying patterns.

Correlational research seeks to determine relationships between variables, identifying whether and how strongly pairs of variables are related. This method does not imply causation, but rather illustrates the possibility of associations, which can be crucial for understanding complex psychological phenomena.

Experimental research stands out by enabling researchers to manipulate one or more independent variables to observe the effect on dependent variables, establishing cause-and-effect relationships. This methodology is essential for drawing conclusions about causal relationships in psychological studies.

The other options, while containing valid research methods, do not encompass the three fundamental categories as concisely or directly as described. Therefore, the combination of descriptive, correlational, and experimental research methods captures the essential frameworks utilized in psychological research, making it the most accurate answer.