In 1986, a total of 11 different populations involving more than 1000 schools and more than 20,000 students participated in the Second IEA Science Study (SISS). This digest discusses findings related to curricular patterns and student outcomes. Ratings were done at grades 5, 9, and 12, to ensure that the achievement tests reflected the science curriculum of the countries involved. The three curricular grids which were designed to follow international guidelines were: traditional science domains; applied/integrated science; and science processes, practical skills, and attitudes. The review of student outcomes compares the 1986 results with earlier tests. These comparisons resulted in mixed findings. (CW)