Mrs. Lee is a junior high school teacher. She is told that her first period English class is an honors class and that the students are high achievers. She is also told that her second period class is remedial and the students had previously failed English courses. Mrs. Lee plans her class work accordingly, challenging the honors class and assigning remedial work to the struggling class. At the end of the term, the honors class performs much better than the remedial class. Mrs. Lee is then told that the students in both classes are average and performed the same in previous assessments. What does this experiment illustrate?
