The development of psychological methods for assessing the abilities of deaf students could aid in the formation of educational programs and the provision of vocational guidance. A battery of tests designed to measure a wide range of functions was administered to all eighth grade students, average age 15, in schools for the deaf in Sweden. All tests, with the exception of those intended to measure verbal ability, were nonverbal. Results from the factor analyses showed that whether the tests were speeded or non-speeded influenced the factor structure. Separate analyses of the boys' and girls' results revealed considerable differences in factor patterns, thus suggesting essential differences in the ability structures. For the girls there seemed to be a strong bond between verbal, numerical, and reasoning tests, and for the boys a corresponding bond between spatial, numerical, and reasoning tests. Comparisons of the results for these deaf groups and those typical of normal subjects are noted. It is suggested that if teaching in schools for the deaf were supplemented with more concrete, manipulative materials and visual aids, problem-solving and mathematical ability in deaf students could be more highly developed. Detailed descriptions of the tests employed and analyses of the resulting data are provided. (PR)