The evolution of the school subject Social Studies in Victoria and in the United States of America is traced briefly, and an examination is made of educational objectives which are appropriate to such a subject. Tests are developed to measure achievement of cognitive objectives, encompassing areas named as Knowledge of Terminology in Social Studies, Knowledge of Generalizations in Social Studies, Comprehension in Social Studies, and Reasoning in Social Studies. The final forms of the tests are administered to 287 upper primary school children and descriptive statistics are computed from the results. Factor analysis is applied to the intercorrelations among scores on selected groups of items from the Social Studies tests and a number of marker variables. The sources of variance contributing to scores on the Social Studies tests are examined and some implications are drawn for measurement of cognitive objectives in Social Studies.