In the usual case, the custody evaluator interviews the parents, both together and individually, one or more times. The evaluator also observes the child and the child’s interactions with each parent; and the evaluator may interview other people who are significant in the child’s life. It is not unusual for the professional to administer some standard psychological tests. It may also be helpful to the evaluator to visit the child’s home or to visit the place you are proposing that the child live. In the interest of objectivity, the professional selected for the custody evaluation should not be a person who has previously treated any member of your family. We also recommend that each party pay one-half the costs of the custody evaluation, to avoid the appearance that the professional is a “hired gun” for the parent who pays the fee. Occasionally one parent, or both parents independently, will hire their own expert mental health professional to advocate that parent’s custody position in court. Judges tend, however, to give less weight to experts who have been retained for the express purpose of being partial to one or the other side. In fact, some judges will disregard psychological testimony, which the judge perceives to be biased, in favor of hearing what other witnesses have to say about what they have observed in the interactions between parents and their children. The decision to employ an expert should best be made under advice from an attorney, as such a decision could lead to considerable expense without enhancing the outcome in your favor.