The simplest interpretation of the findings seems to be this. Gross measures of attention are useful in discriminating between the pupil who is responding to stimuli inside the classroom and the one who is not. But the range of stimuli within the classroom is much broader than the category of subject matter relevant thinking. Thus only under certain conditions, perhaps related to reducing the range of potential covert responses of pupils, do we discover a relationship between observed attention and substantive thinking. REFERENCES BLOOM, B. S. Thought processes in lectures and discussions. Journal of General Education, 1953, 7, 160-169. BLOOM, B. S. The thought process of students in discussion. In S. J. French (Ed.), Accent on leaching. New York: Hamer. 1954. 1 , KRAUSKOPF, C. J. Use of written responses in the stimulated recall method. Journal of Educational Psgcholoqg, 1963, 64, 172-176. MORRISON, HI C. The practice of teaching in the secondary school. Chicago: University of Chicago Press, 1926. SHANNON, J. R. A comparison of three means for measuring efficiency in teaching Journal of E d wtional Research, 193536, 29, 501-508. SHANNON, J. R. A measure of the validity of attention scorm.Several years ago we2 began what we thought was a relatively simple project whose central problem lay in the question, How does a middle class teacher cope with a group of lower class youngsters? The methodology seemed not only simple and naive, but unscientific as well. I proposed to sit in the back of the classroom, observe what the teacher and pupils seemed to be doing and saying, and keep notes of these events. The teacher was to keep a set of notes on his perception of the class and the problems in teaching his group of children. Later we hoped to describe the classroom in considerable detail and to conceptualize the events in more general psychological terms. All of this has come to pass.Apropos of such classroom investigations as the one we carried out, my friend, Bruce Biddle of the University of Missouri, has written that the participant observer methodology is "the broadest and simplest methodology used in classroom