In a review of over 25 empirical investigations of effects of communicating behavioral objectives to students, several trends were apparent. Advance knowledge of behavioral objectives led to improved posttest performance in five of ten studies and to improved retention in two of three instances. Only two of seven studies found an interaction between knowledge of objectives and type of learning: in one case knowledge acquisition but not comprehension was facilitated, while in the other knowledge of objectives interfered on a problem-solving task, but not on a discrimination task. A third group of studies reported interactions between availability of objectives and reasoning ability, personality characteristics, and state anxiety. Finally, when coupled with complete learner control of the course, knowledge of objectives decreased learning time. (Author/RH)