Personal construct theory or personal construct psychology (PCP) is a theory of personality and cognition developed by the American psychologist George Kelly in the 1950s.[1] From the theory, Kelly derived a psychotherapy approach and also a technique called the repertory grid interview that helped his patients to analyze their own constructs (schemas or ways of seeing the world) with minimal intervention or interpretation by the therapist.[2] The repertory grid was later adapted for various uses within organizations, including decision-making and interpretation of other people's world-views.[3]

Kelly explicitly stated that each individual's task in understanding their personal psychology is to put in order the facts of his or her own experience. Then the individual, like the scientist, is to test the accuracy of that constructed knowledge by performing those actions the constructs suggest. If the results of their actions are in line with what the knowledge predicted, then they have done a good job of finding the order in their personal experience. If not, then they can modify the construct: their interpretations or their predictions or both. This method of discovering and correcting constructs is simply the scientific method used by all modern sciences to discover the truths about the universe we live in.

Kelly proposed that every construct is bipolar, specifying how two things are similar to each other (lying on the same pole) and different from a third thing, and they can be expanded with new ideas.

The UK Council for Psychotherapy, a regulatory body, classifies PCP therapy within the experiential subset of the constructivist