This paper describes two empirical studies which investigated the importance for spatial learning of view control and object manipulation within 3D environments. A 3D virtual chemistry laboratory was used as the research instrument. Subjects, who were university undergraduate students (34 in the first study and 80 in the second study), undertook tasks in the virtual laboratory and were tested on their spatial knowledge through written tests. The results of the study indicate that view control and object manipulation enhance spatial learning but only if the learner undertakes authentic tasks that require this learning. These results have implications for educational designers making a choice between video or animation and interactive 3D technologies. The results are discussed within the framework of Piaget's theories on active learning and Gibson's ecological theory of perception and action. (Contains 3 tables and 4 figures.)