Research evidence about the educational effectiveness of animations is mixed. Various investigations have compared the educational effectiveness of static and animated displays across a number of content domains. While there have been some findings that show positive effects of animations on learning, other studies have found no effects or even negative effects. Some propose that the efficacy depends on the way the animation characteristics engages the psychological functioning of the learner. In general, it can be concluded that animations are not "intrinsically" more effective than static graphics. Rather, the particular characteristics of individual animations and how they are used to play a key role in the effects that they have on learning.