Where minor children of the parties are involved, child support, child custody and visitation arrangements must be agreed upon or determined.  Child support is normally fixed pursuant to the California Child Support Guideline, a complex formula which takes into account the earnings of each parent, the number of children involved, and the time-sharing arrangements between the parents.  For parents who generally agree on custody and visitation issues, it is nevertheless often useful to work out details such as holiday schedules, vacations, transportation, and so forth.   If parents do not agree on custody or visitation matters, custody mediation is normally required by the court.  In some cases, psychological experts are employed to prepare an in-depth custody evaluation and a recommendation for the court.  In the usual case, this recommendation will become the basis for an agreement regarding custody.  If the parents remain unable to agree, they are entitled to a trial on the issues of custody and visitation, at which time the court will consider all of the evidence, including the evaluator’s recommendation, and will then make the final determination based on an assessment of what is truly in the best interests of the child or children.