In this paper, an estimator of finite population variance proposed by Isaki (1983) is studied under the two different situations of random non-response suggested by Tracy and Osahan (1994). A distribution is proposed for the number of sampling units on which information could not be obtained due...

Few studies offer a theoretical explanation of the differential effects of massed and spaced advertising. Consequently, conclusions have been mixed. The authors introduce the stimulus sampling model of spacing effects based on Estes' mathematical learning theory. The model posits that massed...