Supporting Coherence Formation in Learning from Multiple Representations

Multimedia learning environments combine multiple forms of representations like texts, static and animated pictures or graphs. Knowledge acquisition from multiple representations requires that learner create referential connections between corresponding elements and corresponding structures in different representations. As this process is usually difficult, learners frequently fail to construct coherent mental representations and, thus, do not sufficiently understand the subject matter. This paper analyzes the effects of different kinds of instructional help on the process of coherence formation from multiple representations by learners with different prior knowledge. Three groups of university students with different domain-specific knowledge had to learn a complex subject matter from chemistry using six different forms of representation. In addition, a first group received directive help for coherence formation. A second group received non-directive help, and a third group received no instructional help. Results indicate that directive help is effective for recall performance because of its summarizing and repeating function. Furthermore learners with different levels of prior knowledge show different reactions when help is given. For learners with insufficient prior knowledge help is not helpful or in case of recall performance even harmful. Learners with a medium level of prior knowledge can increase especially their comprehension performance when help is offered whereas learners with too much prior knowledge seem not to be affected from help. Theoretical background Multiple representations can serve many functions for learning. First, multiple representations may complement each other with regard to their content, their computational efficiency and with regard to learner characteristics and preferences. A second function is that multiple representations may constraint the interpretation of another representation (Ainsworth, 1999). The combination of representations enables learners to deal with the material from different perspectives and with different strategies, as in the case of dynamically linked learning environments, where for example an exchange of variables in a formula is directly displayed as an exchange of graphs. The manipulation of two different representational formats supports two different ways of insight to the same learning content and may have synergetic effects on the construction of coherent knowledge structures. However, this synergy does not emerge per se. Learners must interconnect the external representations and actively construct a coherent mental representation in order to benefit from the complementing and constraining functions of multiple representations. Many studies have shown that learners often do not use multiple representations effectively (van Someren, Reimann, Boshuizen & deJong, 1998). Especially learners with low prior knowledge often have problems with the co-ordination and integration of multiple representations (Yersuhalmy, 1991; Kozma & Russell, 1996). They do not use different representations but rather concentrate only on one representation, often the more familiar or concrete one (Scanlon, 1998; Tabachnek & Simon, 1998; Cox & Brna, 1995). These learners only switch between representations in the case of problems in understanding the actually employed representation (Tabachnek & Simon, 1998). These findings indicate that learners should get support in their coherence formation process in order to benefit from multiple representations. As coherence formation requires that the learners create referential connections between corresponding elements and corresponding structures in different representations, the notion of structure mapping can be used as a conceptual tool to analyze this process (Gentner & Markmann, 1997). If a learner is offered a text and a picture, he or she has to understand the information from both sources. In text comprehension, this includes searching for relevant elements and identifying the relevant relations between those elements within the text. In picture comprehension, a