The problem of this study was to compare the achievement and attitude of students in an individualized biology program, modeled after parts of the Proposed Texas Science Framework, with the achievement and attitude of students in conventional biology classes. The subjects used for the study were tenth grade, first year biology students in three high schools in a large North Central Texas city. Each of the three high schools was selected to represent a particular category of high schools. The categories were based upon the mean achievement scores for the students within a school. The categories of schools were above average, medium low, and very low. In each of the schools the classes and teachers in the experimental group and the control group were matched as closely as possible.