Each school year the frequency of evaluation must be as follows:

(1) All certificated support personnel must be observed for the purposes of evaluation at least twice in the performance of their assigned duties.

(2) New employees must be observed at least once for a total observation time of thirty minutes during the first ninety calendar days of their employment period.

(3) An employee in the third year of provisional status must be observed at least three times in the performance of his/her duties and the total observation time for the school year must not be less than ninety minutes.

(4) Total observation time for each employee for each school year must be not less than sixty minutes: Provided, that after an employee has four years of satisfactory evaluations, a school district may use a short form evaluation pursuant to RCW 28A.405.100(11).