Volume 3, Issue 3, Special issue : Task Models

Year 2014 - Special Issue

Guest editors: Sybille Caffiau & Celia Martinie

Task modeling is a user-centered design technique recognized and used by experts in the fields of HCI, human factors and ergonomics.  This technique provides support for analyzing, designing and evaluating interactive systems. In particular, it is a key technique to analyze user tasks and to provide support for gathering user needs.

Since Duncan et al.’s seminal work at the end of the sixties, several contributions have been proposed to improve task modeling approaches and to increase their integration in several application domains (teaching, interactive system design, activity analysis…). These contributions deal with the definition of notations and methods to model tasks but also with the development of computer-aided software tools for experts in interactive system design and evaluation.

The special issue of the working group “Modèles de taches” is the result of a larger initiative from the AFIHM group. This initiative tends to promote and encourage task modeling in HCI. This special issue is one of the multiple activities that are led to focus attention on recent advances on the task modeling topic.

This special issue presents new contributions about the expressive power of notations, methods for task modeling, and computer-aided software tools for the editing and the simulation of task models. The results presented in this issue are the outcome of the work of the authors as well as the collaborative effort of a community of researchers who are interested in the use and development of task models. This community is larger than the members of the working group “Modèles de Tâches”.

In addition to the authors and reviewers who took care of the scientific quality of this special issue, we would like to thank Joëlle Coutaz, Patrick Girard and Philippe Palanque for their support and advices throughout the editorial process.

Sybille Caffiau, LIG, Université Joseph Fourier, Grenoble I

Célia Martinie, IRIT, Université Paul Sabatier, Toulouse 3


1. Task model simulators: a review

Thomas Lachaume ; Laurent Guittet ; Patrick Girard ; Allan Fousse.
La description de l’activité humain-système par des modèles de tâches existe depuis plusieurs années. Après l’époque papier-crayon, les outils d’édition des modèles de tâches ont permis la conception et l’archivage des modèles selon une notation rigoureuse, et la vérification de leur cohérence. Mais la compréhension de la dynamique est restée affaire de spécialiste jusqu’à l’apparition des simulateurs de modèles. Une simulation permet d’appréhender les enchaînements réels de tâches - décrits implicitement par les opérateurs temporels - et de valider les scénarios ainsi réalisés. Cet article décrit et compare les simulateurs actuellement disponibles et maintenus, et explique leurs différents usages en fonction des buts et niveaux d’expertise des utilisateurs. De nouvelles perspectives d’évolutions de ces modèles et outils sont alors définies dans le but d’améliorer leur sémantique.

2. Un modèle de tâches exploitable à l'exécution pour une assistance à l'utilisateur dans les environnements ambiants

Asma Gharsellaoui ; Yacine Bellik ; Christophe Jacquet.
Existing task models have often been used in the context of graphic systems. In this paper, we propose to use the task model at runtime to monitor user actions, to verify that he/she has not made a mistake when performing his/her actions and to give him/her help when necessary. In particular, we present, as a first contribution, a task model specific to interactions in ambient environments. This model enables to assign dynamic characteristics to each task thereby allowing to a supervision system to assign states to tasks at runtime based on the information exchanged with the environment (start of a task, end of a task, preconditions states...). Our second contribution is a monitoring and support system that exploits our task model. More precisely we specify the intervention strategy of our system in order to guide the user. We present then an illustration of our system through the execution of a scenario on our simulator. This simulation shows how the interactions with the task model at runtime allow us to produce a dynamic system that takes into consideration the context and provides assistance to the users while carrying out their daily tasks. Finally, we end with a conclusion and perspectives of our approach.

3. Description of tasks with multi-user multimodal interactive systems: existing notations

Frédéric Jourde ; Yann Laurillau ; Laurence Nigay.
Multi-user multimodal interactive systems involve multiple users who can use multiple interaction modalities. Multi-user multimodal systems are becoming more prevalent, especially systems based on large shared multi-touch surfaces or video game centers such as Wii or Xbox. In this article we address the description of the tasks with such interactive systems. We review existing notations for the description of tasks with a multi-user multimodal interactive system and focus particularly on tree-based notations. For elementary tasks (e.g. actions), we also consider the notations that describe multimodal interaction. The contribution is then a comparison of existing notations based on a set of organized concepts. While some concepts are general to any notation, other concepts are specific to human-computer interaction, or to multi-user interaction and finally to multimodal interaction.