In an experimental study, the role of temporal variation of a realistic animation was examined. The animation of a complex mechanical system, a pendulum clock, was presented in a between subject design at normal or fast speed. Presentation speed was found to affect distribution of attention and understanding of the functionality of the clockwork mechanism. Verbal reports in the fast condition contained more statements on the weight, which is a central part of the clocks' mechanism. When giving a written description of the clock, subjects who saw the fast presentation produced more correct and less false concepts about the key components of the clockwork. For complex subject matter, it seems possible that speed could be used strategically by instructional designers to raise the perceptual salience of thematically relevant aspects of the display, by means of faster or slower presentation speeds.
Instructional Uses of Temporal ManipulationsThis paper focuses upon temporal properties of a dynamic display and explores the effect of presentation speed on the processing of information in an animated depiction of a complex mechanical device (a pendulum clock). Dynamic visualizations of various types are increasingly used in educational resources for presenting subject matter that involves change over time. Intuitively, these representations appear well suited to helping learners understand change phenomena because they provide explicit depiction of the referent situation's dynamics instead of requiring the learner to reconstruct the dynamics via mental animation from static graphics. Nevertheless, dynamic visualizations have not proven to be a universal panacea for the challenges involved in comprehending change phenomena. Merely providing changerelated information as an analogue dynamic representation does not guarantee that learners will necessarily be able to extract its key aspects (Lowe, 1999(Lowe, , 2003(Lowe, , 2004. Particularly when the subject matter is complex and unfamiliar, learners appear to respond to the consequent high level of information processing demands by selectively attending to aspects of the display that have greatest perceptual salience relative to the rest of the display. Unfortunately, such aspects are not necessarily those of most relevance to the central theme of the presentation. Both the visuospatial characteristics of a dynamic visualisation (such as the size, shape, colour, and arrangement of its component entities) and its temporal properties (such as playing speed, direction, and continuity) have the potential to affect the relative perceptual salience of displayed information. Accordingly, research into learning from dynamic visualizations has produced mixed findings. For example, while Schwan and Riempp (2004), found that usercontrollable videos facilitated the learning of knot-tying tasks, no corresponding facilitation effect was found in studies by Lowe (2003) of learning meteorological prediction skills from a user-controllable weather map animation. A likely reason for ...