This seven-chapter report presents information on the 1980 assessment of students' science performance in the province of Manitoba. Chapter I describes the nature of and steps involved in the assessment. Chapters II, III, and IV present, analyze and discuss achievement and attitude results for grades 5, 8, and 11, respectively. Achievement results are in these categories: knowledge, comprehension, application for three content areas (earth and space science, biological science, and physical science); higher cognitive levels for all three content areas; basic processes; integrated processes; safety; and the nature of science. Attitude results are in these categories: interest in science and science-related activities, attitude toward scientists and science-related areas; and interest in science as a career. Chapter V compares trends in goal achievement (related to achievement result categories), achievement differences according to sex, and trends on common achievement and attitude items. Chapter VI presents results of separate surveys of fifth-, eighth-, and eleventh-grade teachers on their teaching practices, degree of implementation of recently developed science curricula, background, and other areas. (Survey instruments are included in appendices). Chapter VII summarizes findings and offers recommendations related to grade level and to achievement/attitude result categories. (JN)