Natural streams (those not "adjusted" by humans) meander. Their water moves slower. They exist in alternating areas of deep pools and shallow ripples. These alternating areas have ecological importance, providing habitat to different kinds of aquatic organisms. These streams contain rocks of many sizes that provide great homes for algae. They don't move water as fast, and they get in the way of farming with all their meandering.
You may be wondering when I'm going to get to the point. This is, after all, a science blog. I began to think about these two streams as a metaphor for science instruction. We can make science instruction unnatural--a straight path through which we can move kids quickly. Many examples of curricula do this. It's much easier and quicker to have students memorize the definition of inertia instead of having them experience it and develop deep understanding. It's easier and quicker to design a curriculum of telling students about science as opposed to having them figure out phenomena.
Just as the health of the stream is affected when we straighten it, the science understanding of our students is affected when we "straighten" and streamline the curriculum. The stream loses biodiversity and transports pollution much easier. The students of a streamlined curriculum end of memorizing a lot of "stuff" that they will soon forget, while failing to develop lasting skills and understandings of science.
During this summer break, think about your curriculum. Is it like the straightened stream--standardized for efficiency, or is it like a meandering stream--moving at the pace required for true science understanding? How can you move your curriculum towards that meandering stream metaphor?