A similar idea is called the Inductive Learning Strategy. It is done before teaching a concept or reading a large non-fiction text. Clues about a concept are passed out one to each member of a group. From here the students group the clues and discuss why they are important and how they connect. They draw conclusions based on the clues. They then present their ideas to the class. It is fun, especially in Social Studies. I have also used it to introduce novels or short stories.
Once the reading begins or the concept is introduced the students have to look for evidence that either supports their ideas, or not. It gives them a purpose for reading.