Key points are not available for this paper at this time.
Written educational selections and cartoons drawn to illustrate different educational points were arranged to effect a factorial variation in (1) level of difficulty of educational material (easy, difficult) and (2) amount of humor (no humor, moderate humor, extensive humor). Students read one version, evaluated it on a number of dimensions, and were tested over the material. Pictorial humorous illustrations were found to have no effect on information acquisition and on motivation, positive effects on appeal, and negative effects on persuasibility.
Bryant et al. (1981) studied this question.