Psychology is, like any science, a branch of knowledge that deals with a body of facts systematically arranged and shows the operation of general laws.
In all sciences, including psychology, a special procedure, the scientific method, must be used to collect data to answer a question or to solve a problem. The scientific method not only answers the question at hand but also is used to construct scientific theories. A theory is systematically organized knowledge applicable in a wide variety of circumstances. (The amount of information available in any science is too vast to be useful unless it is organized through the use of theories.) Theories are also used to predict events or to answer questions in a specific scientific discipline. In psychology, theories are used to organize and predict behavior and mental processes. The findings of a particular study may support or lead to the alteration of a theory.
While the scientific method doesn't provide a step‐by‐step recipe for dealing with specific circumstances, it does provide general guidelines for the following procedures in any scientific data collection.
The description of a study, its procedures, and its conclusions is frequently published as an article in a scientific journal. Careful attention to following the scientific method allows a second investigator to replicate or refute the findings of a study. For ease of replication, the variables (items under consideration in a study that can change or vary during the course of the study) in a study are defined in terms of observable operations called operational definitions.