  Instructors in introductory physics courses often use labs and demonstrations
to reinforce that the physics equations introduced in lectures and textbooks
describe what actually happens in the real world. The surface features and
instructional learning goals of such labs and demonstrations may seem quite
similar (predict-observe-explain). Nonetheless, physics education research has
found very different impacts of these instructional methods on students'
physics content knowledge that depend critically on several instructional
characteristics. In this paper, we disentangle the research by comparing
details of the learning methods in verification labs, traditional lecture
demonstrations, and enhanced lecture demonstrations. We discuss possible
mechanisms for the measurably different learning outcomes by dissecting the
activities according to the role of prediction, cognitive load, and engagement.
We use this characterization to motivate rethinking the goals of labs towards
experimentation skills and beliefs, rather than for verifying physics content.
