Despite those mostly positive research results, interest in mastery learning strategies decreased throughout the 1980s, as reflected in publication activity in professional journals and presentations at conferences. Many explanations were put forward to justify this decline, like alleged recalcitrance of the educational establishment to change, or the ineffective implementations of mastery learning methods, or the extra time demanded in setting up and maintaining a mastery learning course or even concerns that behavioristic-based models for teaching would conflict with the generally humanistic-oriented teachers and the surrounding culture.