The International Association for the Evaluation of Educational Achievement (IEA) Science Project encompasses three countries--Australia, the Federal Republic of Germany, and the United States. It is considered Phase II of the project, with a Mathematics Study completed in 1967 as Phase I. A background paper is presented to include in tabulated form a list of countries taking part in the IEA Science Project and shows the levels at which participation was taken. The construction of the instruments for the project is described. A cognitive list in science for three levels of testing was developed: 10-year-olds, 14-year-olds, and the pre-university grade. The project also attempted to assess certain non-cognitive outcomes of science education. These assessments are presented and discussed. Questionnaires used, data collection procedures, and data analyses are presented. Results of a survey across countries attempting to determine factors in the education process which influenced the achievement of students in science are presented in tabulated, graphical, and descriptive forms. A discussion summarizes the author's conclusions and comments. (EB)