Hess (1987, 1999) discusses at least seven different dimensions along which psychology and law ...

a.   Knowledge
•   In psychology, knowledge is gained through cumulative research.
•   In the law, knowledge is acquired through precedent, logical thinking, and case law.
b.   Methodology
•   In psychology, methods are predominantly nomothetic (i.e., goal is to uncover general trends and processes).
•   In the law, the methodological approach is idiographic (i.e., operates on a case-by-case basis).
c.   Nature of law
•   Psychology is descriptive, the goal being to describe how people behave.
•   Law is prescriptive, telling people how they should behave.
d.   Epistemology
•   In psychology, it is assumed that there is an objective truth that can potentially be uncovered using the experimental method.
•   In the law, truth is defined subjectively and is based on who can present the most convincing argument.
e.   Principles
•   In psychology, alternative explanations are considered (i.e., falsifiability).
•   The lawyer’s goal is to convince the court that his/her explanation is solely correct.
f.   Criteria
•   Psychology is cautious and conservative in accepting a hypothesis as true (results must be replicated, etc.).
•   Law decides truth on the basis of a single case and a criterion that is far more lenient.
g.   Latitude
•   The behaviour of a psychologist providing expert testimony in court is severely restricted.
•   The behaviour of a lawyer within the court is subject to far fewer restrictions.
The student need only provide four of the seven dimensions to receive full marks.