McKeown, Margaret G. and Isabel L. Beck. “The Assessment and Characterization of Young Learners’ Knowledge of a Topic in History.” American Educational Research Journal 27(4) (1990): 688-726.
The knowledge that 35 fifth graders and 37 sixth graders had about a historical period was characterized by focusing on the fifth graders before they studied the Revolutionary War, and sixth graders 1 year after they studied the topic. Students' knowledge before and after instruction included simple associations and lacked connected structures.