Sébastien Lallé

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User performance and satisfaction when working with an interface is influenced by how quickly the user can acquire the skills necessary to work with the interface through practice. Learning curves are mathematical models that can represent a user's skill acquisition ability through parameters that describe the user's initial expertise as well as her(More)
We describe a method to evaluate how student models affect ITS decision quality – their raison d'être. Given logs of randomized tutorial decisions and ensuing student performance, we train a classifier to predict tutor decision outcomes (success or failure) based on situation features, such as student and task. We define a decision policy that selects(More)
This paper summarizes an ongoing multi-year project aiming to uncover knowledge and techniques for devising intelligent environments for user-adaptive visualizations. We ran three studies designed to investigate the impact of user and task characteristics on user performance and satisfaction in different visualization contexts. Eye-tracking data collected(More)
A bstract. Previous works have pointed out the crucial need for comparison between knowledge diagnostic tools in the field of Intelligent Tutoring Systems (ITS). In this paper, we present an approach to compare knowledge diagnostics. We illustrate our proposition by applying three criteria of comparison for various diagnostic tools in geometry. In the field(More)
Confusion has been found to hinder user experience with visualizations. If confusion could be predicted and resolved in real time, user experience and satisfaction would greatly improve. In this paper, we focus on predicting occurrences of confusion during the interaction with a visualization using eye tracking and mouse data. The data was collected during(More)
Our aim is to develop a Fuzzy Logic based student model which removes the arbitrary specification of precise numbers and facilitates the modelling at a higher level of abstraction. Fuzzy Logic involves the use of natural language in the form of If-Then statements to demonstrate knowledge of domain experts and hence generates decisions and facilitates human(More)
Confident usage of information visualizations is thought to be influenced by cognitive aspects as well as amount of exposure and training. To support the development of individual competency in visualization processing, it is important to ascertain if we can track users’ progress or difficulties they might have while working with a given visualization. In(More)
We propose a method and a first authoring tool to assist the design and implementation of diagnostic techniques. This method is independent from the domain and allows building more than one technique at once. The method is based on knowledge representation and a semi-automatic machine learning algorithm. We tested the method in two domains, surgery and(More)