Once over the initial hurdle of introducing the central idea, we decided to use a strategy called "Think, Puzzle, Explore" from "Making Thinking Visible" by Ritchhart, Church and Morrison (2011). This is very similar to a KWL chart, but I think it better models the tentative nature of our knowledge through its three questions and it invites student voice into the unit.
1). What do I THINK I know about this unit?
2). What PUZZLES me about this unit?
3). What or how do I want to EXPLORE this unit?
We divided the class into 3 groups and placed an adult helper with each group (helpful for scribing with little ones). The groups then had 10 minutes to respond to the question on a poster. They then rotated so each child had the chance to respond to each question. I had found a picture diagram of an ecosystem. It was a simple line-sketch with no words of a deer in the woods, by a clearing, with bushes, grasses and trees, the sun and a rain cloud. There was even an underground river. The whole picture was marked with directional arrows between the elements. I placed this picture at the centre of each poster. I think the highlight of the lesson was when one lad, pointing at the picture, exclaimed, "But how does it all connect? How does it all go together?" - Now we were ready to begin.