Graphics have been used since ancient times to portray things that are inherently spatiovisual, like maps and building plans. More recently, graphics have been used to Portray things that are metaphorically spatiovisual, like graphs and organizational charts. The assumption is that graphics can facilitate comprehension, learning, memory, communication and inference. Assumptions aside, research on static graphics has shown that only carefully designed and appropriate graphics prove to be beneficial for conveying complex systems. Effective graphics conform to the Congruence Principle according to which the content and format of the graphic should correspond to the content and format of the concepts to be conveyed. From this, it follows that animated graphics should be effective in portraying change over time. Yet the research on the efficacy of animated over static graphics is not encouraging. In cases where animated graphics seem superior to static ones, scrutiny reveals lack of equivalence between animated and static graphics in content or procedures; the animated graphics convey more information or involve interactivity. Animations of events may be ineffective because animations violate the second principle of good graphics, the Apprehension Principle, according to which graphics should be accurately perceived and appropriately conceived. Animations are often too complex or too fast to be accurately perceived. Moreover, many continuous events are conceived of as sequences of discrete steps. Judicious use of interactivity may overcome both these disadvantages. Animations may be more effective than comparable static graphics in situations other than conveying complex systems, for example, for real time reorientations in time and space. #

Abstract-This paper proposes to maintain player's engagement by adapting game difficulty according to player's emotions assessed from physiological signals. The validity of this approach was first tested by analyzing the questionnaire responses, electroencephalogram (EEG) signals, and peripheral signals of the players playing a Tetris game at three difficulty levels. This analysis confirms that the different difficulty levels correspond to distinguishable emotions, and that, playing several times at the same difficulty level gives rise to boredom. The next step was to train several classifiers to automatically detect the three emotional classes from EEG and peripheral signals in a player-independent framework. By using either type of signals, the emotional classes were successfully recovered, with EEG having a better accuracy than peripheral signals on short periods of time. After the fusion of the two signal categories, the accuracy raised up to 63%.

Computer animation has a tremendous potential to provide visualizations of dynamic phenomena that involve change over time (e.g., biological processes, physical phenomena, mechanical devices, historical development). However, the research reviewed in this chapter showed that learners did not systematically take advantage of animated graphics in terms of memorization and comprehension of the underlying causal or functional model. This chapter reviewed the literature about the interface and content features that affect the potential benefits of animation over static graphics. Finally, I proposed some guidelines that designers should consider when designing multimedia instruction including animation. What Are the Animation Principle and the Interactivity Principle? In the last decade, with the rapid progression of computing capacities and the progress of graphic design technologies, multimedia learning environments have evolved from sequential static text and picture frames to increasing sophisticated visualizations. Two characteristics appear to be essential to instruction designers and practitioners: the use of animated graphics as soon as depiction of dynamic system is involved, and the capability for learners to interact with the instructional material. Conceptions of animation. Despite its extensive use in instructional material, computer animation still is not well understood. Baek and Layne (1988) defined animation as "the process of generating a series of frames containing an object or objects so that each frame appears as an alteration of the previous frame in order to show motion" (p. 132). Gonzales (1996) proposed a broader definition of animation as "a series of varying images presented dynamically according to user action in ways that help the user to perceive a continuous change over time and develop a more appropriate mental model of the task" (p. 27). This definition however contained the idea that the user interacts with the display (even minimally by hitting any key). In this chapter we do not restrict animation to interactive graphics, and choose Betrancourt and Tversky's (2000) definition: "computer animation refers to any application which generates a series of frames, so that each frame appears as an alteration of the previous one, and where the sequence of frames is determined either by the designer or the user" (p 313). This definition is broader by design than either of the preceding definition. It does not stipulate what the animation is supposed to convey, and it separates the issue of animation from the issue of interaction. According to Schnotz and Lowe (2003), the concept of animation can be characterized using three different levels of analysis: Technical, semiotic and psychological. The technical level refers to the technical devices used as the producers and carriers of dynamic signs. With the evolution of the computer graphics industry, distinguishing between events captured by way of a camera or events completely generated by computer is becoming harder and irrelevant to learning i...

No abstract

This paper proposes an approach based on emotion recognition to maintain engagement of players in a game by modulating the game difficulty. Physiological and questionnaire data were gathered from 20 players during and after playing a Tetris game at different difficulty levels. Both physiological and self-report analyses lead to the conclusion that playing at different levels gave rise to different emotional states and that playing at the same level of difficulty several times elicits boredom. Emotion assessment from physiological signals was performed using a SVM (Support Vector Machine). An accuracy of 53.33% was obtained on the discrimination of three emotional classes, namely boredom, anxiety, engagement.