An integrated model of multimedia effects on learning.

Research on multimedia and related instructional technologies over many years has been characterized by inconsistent findings about their effects on learning. This is because of the myriad of contingent factors that have been shown to moderate multimedia effects. This article offers a model that is designed to integrate the main elements identified in the literature and also to describe their key inter-relationships. There are 12 elements in the model, each representing a theoretical construct, which can be operationalized as a variable. Learner style constitutes the independent variable, with learning as the dependent variable. The other elements are visual input, auditory input, learner control, attention, working memory, motivation, cognitive engagement, intelligence, reflection, and long-term storage, each of which is either an intervening or moderating variable or in some cases both. The elements in the model have causal or associative links with other elements. The proposed model is seen as useful in hi ghlighting the complex nature of multimedia effects on learning and in fostering instructional design which addresses this complexity. ********** A fundamental question about multimedia effects on learning is why some research studies show positive effects, others null effects with some even showing negative effects. There are many studies reporting that educational multimedia can have a positive impact on learning. A meta-analysis by Liao (1998), for example, examined 35 studies and concluded that multimedia-based instruction is superior to traditional instruction. However, it is notable that 10 of these 35 studies showed the opposite, namely, that traditional instruction is superior to multimedia. A subsequent meta-analysis of 46 studies (Liao, 1999) confirmed the overall positive effect of multimedia on student achievement, but found that it largely depends on what type of instruction it is being compared with. Further, a review of 30 experimental studies on the effects of multimedia (Dillon & Gabbard, 1998) found little evidence that it improves comprehension. It seems clear from these contrasting findings that there are many factors involved in mo derating the effects of multimedia on learning. This article presents an integrated model that is designed to provide a basis for describing the complex relationships among the relevant variables that together determine the impact of multimedia in different learning situations. RESEARCH ON MULTIMEDIA EFFECTS Before the advent of multimedia there was considerable debate, still largely unresolved today, about whether or not media affects learning. Clark (1983) argued that any apparent media effects result from research which confounds the influence of instructional method, that media are "mere vehicles that deliver instruction" (Clark, 1983, p. 445). Later, Clark concluded that "Media and their attributes have important influences on the cost or speed of learning but only the use of adequate instructional methods will influence learning (Clark, 1994, p. 27). Several writers, however, have questioned the value of such "media-centred debate" (Jonassen, Campbell, & Davidson, 1994, p. 31) and suggest approaching the question not in terms of whether media affect learning but rather by asking: "In what ways can we use the capabilities of media to influence learning for particular students, tasks, and situations? " (Kozma, 1994, p. 18). One instructional technology, which has a reasonably long history in education, is interactive video where the learner's response determines the order and type of content. A meta-analysis of 63 studies of achievement outcomes with interactive video examined 100 effect measures and found that 51 effects were significantly positive and 5 were significantly negative, the remainder being nonsignificant (McNeil & Nelson, 1991). Why the variation in findings? …