Results from the first year of a three-year longitudinal study (grades 6-8) of sex-related differences are reported. The purposes of the study are: (1) to understand more adequately the impact of one important cognitive influence (Spatial Visualization) on the learning of mathematics, and (2) to identify educational influences on the development of feelings of confidence in the learning of mathematics. Influences on confidence are being studied by observing classroom interactions and by a projective-type interview. Subjects in this portion of the study are above the mean in achievement and either high or low in confidence in learning mathematics. The impact of spatial visualization skills on the learning of mathematics is being studied in a one-to-one interview with subjects who are discrepant in spatial/verbal skills. They are asked to solve pictorial or analytic word and fraction problems. Transcribed interviews are coded for verbal information, picture information, picture use, mental movement, and scores. (Author/MK)