A custody evaluation includes interviews, psychological testing and home visits often undertaken by a mental health professional who is called a guardian ad litem or court investigator. His or her reports sometimes include non-binding recommendations about the best interests of the child.

In custody disputes, the parties often enlist the professional opinion and testimony of a counselor or therapist. The evaluator studies the behavior and emotions of the family relationships and testifies in court or by a deposition to explain his or her conclusions.

The parties should be aware of the differences between a counselor and an evaluator. The evaluator merely studies the family, whereas the counselor not only evaluates but also advises.

Both spouses should mutually consent to an evaluation, and the agreement should be put in writing. One side should never be observed and/or evaluated without the other one present, unless previously notified and authorized.

The evaluator visits the homes of each parent at a time that best demonstrates the typical family atmosphere. While this is not to be a surprise visit, neither is the visit rehearsed. The child must be present at the residence for at least part of the visit.

The evaluator may contact teachers, doctors, baby-sitters, or any other people who enjoy a fairly close relationship with the child.

The evaluator delivers reports to each party concurrently, and a session should be made available in which each parent can address any questions as well as receive information about the child and the family relationships.