6[5]Blaine R. Worthen & James R. Sanders(1981), Education Evaluation: Alternative Approaches and Practical Guidelines [ M ]. New York & London: Longman. 63.65.
10[13]Blaine R.Worthen & James R.Sanders (1981),Education Evaluation: Alternative Approaches and Practical Guidelines [M]. New York & London: Longman. 67,68.