Prior to January 1, 1979, every school board, board of education, or governing board of any educational institution in Nebraska covered by the provisions of sections 79-824 to 79-842 shall adopt a reduction-in-force policy covering employees subject to such statutory provisions to carry out the intent of sections 79-846 to 79-849. No such policy shall allow the reduction of a permanent or tenured employee while a probationary employee is retained to render a service which such permanent employee is qualified by reason of certification and endorsement to perform or, in cases in which certification is not applicable, by reason of college credits in the teaching area. If employee evaluation is to be included as a criterion to be used for reduction in force, specific criteria such as frequency of evaluation, evaluation forms, and number and length of classroom observations shall be included as part of the reduction-in-force policy.