Incremental Principle

Learning situations are ordered in the early stages so that earlier cases lead to generalizations that are fruitful for later cases. When learners face more complex cases later, the learning space (the number and type of guesses the learner can make) is constrained by the sorts of fruitful patterns or generalizations the learner has found earlier.

For more details, see James Paul Gee. What Video Games Have to Teach us About Learning and Literacy (New York: Palgrave Macmillan, 2003).