A seemingly unending controversy in the field of instruction science concerns how much instructional guidance needs to be provided in a learning environment. At the one extreme lies the claim that it is important for students to explore and construct knowledge for themselves, which is often called discovery learning, and at the other extreme lies the claim that providing direct instruction is more beneficial than withholding it. In this article, evidence and arguments that support either of the approaches are reviewed. Also, we review how different instructional approaches interact with other instructional factors that have been known to be important, such as individual difference, self-explanation, and comparison. The efforts to combine different instructional approaches suggest alternative ways to conceive of learning and to test it.