Eight groups of 10 undergraduates each were given a learning task with trigrams having four levels of difficulty which could be accomplished either by meaningful concept learning or by rote memorization. The number of subjects with concept learning set who acquired the concept decreased gradually as difficulty increased but the number of subjects with rote learning set who acquired the concept by incidental learning decreased abruptly to zero. Subjects with concept learning set who learned difficult concepts did so even though it took more trials than were required by subjects with rote learning set learning by memorization.