Cambridge Handbook of Instructional Feedback

"'Feedback, like rain, should be gentle enough to nourish a person's growth without destroying the roots.' This quote (modified from the original by Frank A. Clark) is a simple reminder that feedback can be helpful or not, assume a variety of forms, be provided at different times, and have diverse effects on different people. But what if there were a drought (no rain, no feedback)? Consider the following two questions: If a tree falls in the woods and nobody's around to hear it--does it make a noise? If a teacher instructs some content or skill and doesn't assess and support learning--can students deeply learn? In both cases, the answer is no. So feedback is really important--not just for learning new things, but pretty much across all of life. There are countless examples of feedback in nature--with both positive and negative functions. For example, our hypothalamus reacts to changes in temperature and responds appropriately. If the temperature drops, we shiver to bring up the temperature; and if it's too hot, we sweat to cool down via evaporation. Predator-prey relations in nature are also well-known examples of feedback loops, as is climate change. The key difference between positive and negative feedback is their response to change--positive feedback enlarges change while negative feedback reduces change"--