linical psychologist Gillian Butler (1998, p.2) puts this succinctly:
A formulation is the tool used by clinicians to relate theory to practice... It is the lynchpin that holds
theory and practice together... Formulations can best be understood as hypotheses to be tested.
The Core Purpose and Philosophy of the Profession (DCP, 2010, pp.5-6) states:
Psychological formulation is the summation and integration of the knowledge that is acquired by this
assessment process that may involve psychological, biological and systemic factors and procedures. The
formulation will draw on psychological theory and research to provide a framework for describing a
client’s problem or needs, how it developed and is being maintained. Because of their particular
training in the relationship of theory to practice, clinical psychologists will be able to draw on a number
of models (bio-psycho-social) to meet needs or support decision making and so a formulation may
comprise a number of provisional hypotheses. This provides the foundation from which actions may
derive... Psychological intervention, if considered appropriate, is based upon the formulation.