Abstracts - Earli

epresentation of a transformer to be unproblematic. One student, however, claimed not to haveever understood what was being represented. The student knew the various parts (coils, iron core,currents etc.) but not what the diagram represented as a whole. We also identified situations wherestudents were seemingly ‘fluent’ in a number of representations, but had still not appropriatelyexperienced the associated disciplinary concept. For example, Maxwell’s equations could be usedto calculate correct answers but the meaning of these representations was unclear to students.Referring to the phenomenological concepts of appresentation and relevance structure, and theobservation that different representations have different affordances, our analysis suggests thatfluency in a critical constellation of representations may be a necessary condition for meaningfulaccess to disciplinary concepts. The pedagogical implications of this approach are brieflydiscussed.Utility, usability and acceptability: an ergonomic approach to the evaluation of externalrepresentations for learningAndre Tricot, Work and Cognition Laboratory, Univ. of Toulouse, FranceSince the beginning of information and communication technology, many computer programs forlearning were designed and distributed to schools and universities. But sadly, many of them arenot used. Consequently, it is both interesting and useful to evaluate and to improve these computerprograms before trying to distribute them. Ergonomic approaches attempt to fulfil this type ofgoal: evaluation in order to improve. But these approaches are very often confused with usabilityevaluation. Confusing usability approaches and ergonomic approaches can lead to a deadlock. Weconducted different studies in the evaluation of computer programs, containing a variety ofexternal representations for learning. These studies show that a designed artefact can be usable butnot used, and vice versa. That is the reason why we propose an ergonomic framework where thequality of an artefact is defined by its utility, usability and acceptability. We present data, fromdifferent empirical studies, which allow us to say that these three dimensions are equally importantand interrelate. We also found that these relationships are not always similar. Then, we defend aninductive approach to the analysis of the relationships between utility, usability and acceptability.I 530 August 2007 14:30 - 16:30Room: -1.64SymposiumExploring the nature of the refutation text effect in conceptual changeChair: Suzanne H. Broughton, University of Nevada, Las Vegas, USAOrganiser: Mirjamaija Mikkila-Erdmann, University of Turku, FinlandOrganiser: Gale M. Sinatra, University of Nevada, Las Vegas, USADiscussant: Clark Chinn, Rutgers University, USADiscussant: Erno Lehtinen, University of Turku, FinlandClassroom learning typically involves the restructuring of existing knowledge (Mason & Gava,2005). One instructional tool that has been found to be effective with enriching the potentials oflearning is refutational texts. Refutational texts are designed to activate students’ prior knowledgeby directly stating misconceptions about a topic, refuting those misconceptions, then presenting– 483 –