Several investigations (Rosenthal and Jacobsen, 1968; Lanzetta and Hannah, 1969; Ring and Farina, 1969) have shown that manipulating the information given to a trainer concerning a trainee whom he is to teach results in changes in the trainer's evaluation of the trainee's performan Thus, Rosenthal and Jacobson (1968) told teachers in a public school that certain of their students would show marked improvement during the following year. At the end of the year, those students did show an improvement on standardized measures of achievement and intelligence greater than that found for the general student population.