Julien Cegarra

Contact

My research interests focus on human expertise in optimization-related problems such as industrial planning and scheduling, timetabling, vehicle planning, dispatching or routing. In these domains, I am mainly interested in:

• The design of human-machine cooperation: A number of difficulties in the relationship between human and decision support systems (DSS) have been previously stressed (see for instance, in the case of scheduling situations: Cegarra, 2008). I am particularly interested in the complacency problem i.e. experts operators who are aware of a DSS's limits could adopt its proposal without questioning them (Cegarra & Hoc, in press).
• Individual differences in strategies: In Cognitive Ergonomics, individual differences have mainly been interpreted as expertise effects (e.g., Cegarra & Hoc, 2006). I also attempt to go beyond this traditional approach, referring to the notion of cognitive styles (Cegarra & Hoc, 2006).

HOPS is a research network aiming at increasing knowledge required for improving human performance in industrial planning, scheduling, and control (PSC). HOPS stands for Human and Organizational factors in industrial Planning, Scheduling, and Control and is supported by COST, the European Cooperation in the field of Scientific and Technical research.
I did coordinate an activity about task allocation and was a member of another about acceptance of support systems.

I-desme project aims to develop a framework process for the interdisciplinary design and implementation of production scheduling Decision Support Systems (DSS) in Cypriot Small to Medium Enterprises (SMEs).

I contribute to the SESAR project on WP4 – En-Route Operations. It aims at facilitating a pivotal change in the management of En-Route traffic, and by enabling a much more efficient management of air traffic control

• Bernat Gacias Topic: "An interdisciplinary approach for vehicle routing problem decision support system" (2007-2010). Currently in a post-doctoral position at Ecole des Ponts ParisTech
• Caroline Martin Topic: "Analysis of Mental Workload during En-route Air Traffic Control" (2010-)
• Bérangère Hittinger Topic: "Cooperative activities during vehicle planning and regulation" (2010-)

I am currently assistant professor at the Jean-François Champollion University Centre in Albi (FR).

Teaching areas

• PY0B18: Cognitive Ergonomics / Human Factors (L3)
• PY0001: Cognitive Psychology (L1)
• PY0020: Cognitive Psychology (L3)
• PY0006: Experimental methodology (L1)
• PY0019b: Methods in Psychology (L3)
• Master in Ergonomics / Master en ergonomie :
• MAP1801E: Cognitive Ergonomics (M1)
• MAP1806E: Analysis of dynamic situations (M1)
• MAP1806E: Simulation and modeling (M1)

Other teaching experience

• Cognitive Ergonomics (M2) - Master "Conception, Edition et Gestion des documents", Université de Bretagne-Sud (2004-2006)
• Cognitive Ergonomics of dynamic situations (M2) - Master "Psychologie du travail et ergonomie", Université de Rennes (2003-2004)
• Cognitive Psycholoy and the design of Human-machine cooperation (3rd year students) - Ecole des Mines de Nantes (2003-2004)

Papers submitted for publication (in peer-review journals)

• Cegarra, J., Baracat, B., Rattat, A.-C., & Valax, M.-F. (submitted). Revisiting time estimation as an index of mental workload.
• Gacias, B., Cegarra, J., & Lopez, P. (submitted). Improving human-machine collaboration in transportation scheduling support systems.
• Valax, M.-F., Baracat, B., Cegarra, J., & Rattat, A.-C. (submitted). Time management and prospective memory: Effect of Daylight Saving Time on the arrival time to medical appointments.
• Van Wezel, W., Cegarra, J., & Hoc, J.-M. (submitted). Technology Acceptance and Cognitive Engineering for Interactive Scheduling Algorithms.
• Cegarra, J., & Van Wezel, W. (submitted). Revisiting decision support systems for cognitive readiness: A contribution to unstructured and complex scheduling situations.
• Cegarra, J., & Hoc, J.-M. (submitted). Effet du niveau d’expérience des opérateurs et de la complexité du problème sur les stratégies d’élaboration de plans : une étude auprès de concepteurs d’horaires de trains

Published or accepted articles (in peer-review journals)

• Cegarra, J., Gacias, B., & Lopez, P. (in press). Implications of technological changes in vehicle routing interfaces for planners’ constraint processing. Human Factors and Ergonomics in Manufacturing
• Forrierre, J., Anceaux, F., Cegarra, J., & Six, F. (in press). L'activité des conducteurs de travaux sur les chantiers de construction : ordonnancement et supervision de situation dynamique.
• Cegarra, J., & Chevalier, A. (2008). The use of Tholos software for combining measures of mental workload: towards theoretical and methodological improvements. Behavior Research Methods, 40(4), 988-1000. AbstractAbstract: Mental workload is a central concept in a range of disciplines (including cognitive psychology and ergonomics), and has given rise to various theoretical and methodological debates. As a result, a number of different techniques for measuring mental workload have been used by researchers. Traditionally, three categories of measurement technique are recognized: performance measures (e.g., the dual-task paradigm), subjective measures (e.g., rating scales) and physiological measures (e.g., heart rate, respiration rate and blink rate). Each of these techniques has its advantages and limitations; however, some limitations may prevent an accurate evaluation of the mental workload. In this paper, we focus on the benefits of combining multiple measures of mental workload. However, combining several techniques is a very complex process and we have developed the Tholos software in an attempt to reduce this complexity. This software package uses measures from each of the three categories: (1) a dual-task paradigm with auditory signals, (2) the NASA-TLX scale and its simplified version (RTLX), and (3) an ability to merge protocols from physiological measurements (such as pupil dilation measurements) with results from the dual-task paradigm. In order to illustrate the benefits of using Tholos, we describe a puzzle-solving experiment in which we combined multiple measures of mental workload. The results indicate the importance of combining multiple measures to build upon the theoretical and methodological foundations of mental workload.
• Cegarra, J., & Hoc, J.-M. (2008). The role of algorithm and result comprehensibility of automated scheduling on complacency. Human Factors and Ergonomics in Manufacturing, 28(6), 603-620. AbstractAbstract: Several studies have stressed that even expert operators who are aware of a machine’s limits could adopt its proposals without questioning them (i.e. the complacency phenomenon). In production scheduling for manufacturing, this is a significant problem, as it is often suggested that the machine be allowed to build the production schedule, confining the human role to that of rescheduling. In this article, we evaluated the characteristics of scheduling algorithms on human rescheduling performance, the quality of which was related to complacency. We suggested that scheduling algorithms be characterized as having result comprehensibility (the result respects the scheduler’s expectations in terms of the “discourse rules” of the information display) and/or algorithm comprehensibility (the complexity of the algorithm hides some important constraints). Our findings stress, on the one hand, that result comprehensibility is necessary to achieve good production performance and to limit complacency. On the other hand, algorithm comprehensibility leads to poor performance due to the very high cost of understanding the algorithm.
• DownloadCegarra, J. (2008). A cognitive typology of scheduling situations: A contribution to laboratory and field studies.Theoretical Issues in Ergonomics Science, 9(3), 201-222. AbstractAbstract: Scheduling activities are carried out in the domains of industry (production scheduling), personnel (nurse scheduling) and transportation (train scheduling). Nevertheless, there is little available knowledge on how operators schedule. In general, laboratory studies have been found to be not entirely representative of real situations (i.e. there are problems of ecological validity). Furthermore, it is difficult to make generalizations because field studies are usually conducted with just one scheduler. To overcome these two issues, this paper suggests bringing laboratory and field studies closer together using a cognitive typology. First, typologies that do not explicitly refer to a cognitive point of view are discussed. Then, the properties of a cognitive typology are detailed. A cognitive typology specific to scheduling situations is presented. This typology associates seven dimensions with their related human strategies: complexity, uncertainty, time pressure, cycle synchronicity, process steadiness, process continuity, and multiple and contradictory objectives. For each dimension, the theoretical, methodological and practical implications are detailed.
• Chevalier, A., & Cegarra, J. (2008). Une approche psychologique de la notion de contraintes en résolution de problèmes [A psychological approach of constraints in problem-solving]. Le Travail Humain, 71, 173-198. AbstractRésumé : Ce texte propose une synthèse des travaux conduits sur la notion de contrainte en psychologie cognitive et ergonomique, en s'appuyant également sur des recherches issues de l'intelligence artificielle (I.A.). La notion de contraintes se retrouve fréquemment dans la littérature scientifique au sein de ces deux disciplines, sans pour autant qu'un travail de synthèse n'ait été réalisé. C'est dans l'objectif de remédier à cette limite que ce travail s'inscrit, en nous focalisant plus particulièrement sur les situations individuelles de résolution de problèmes. La première partie de ce travail est consacrée à la présentation des différentes définitions et typologies de contraintes que l'on retrouve dans la littérature, en proposant des mises en relation entre les typologies rencontrées. La seconde partie expose les opérations qui sont effectués sur les contraintes (notamment la formulation, la propagation et la satisfaction), en proposant également des mises en relation entre les différentes approches présentées. Nous concluons ce travail par la proposition de pistes de recherche et de réflexion à approfondir que suggère l'état d'avancement de la recherche s'intéressant aux contraintes.
  
  Abstract: Many studies have been conducted on the role of constraints in psychology and artificial intelligence (A.I.) since the sixties. In psychology as well as in A.I., these studies were led in various problem-solving domains, such as design or scheduling problems, cooperative or individual problems. Although many definitions and approaches to constraints were suggested, no synthesis article has already been realized. This is the purpose of our present paper. This paper reviews the researches conducted in cognitive and ergonomic psychology that tackle the role of constraints, and includes the main studies from A.I. used in psychology. As most studies focused on the role of constraints in individual problem-solving situations, we chose to attend more precisely to these activities and to illustrate them with various examples from empirical studies. This review starts with the presentation of the main definitions, typologies, and statuses often attributed to constraints in psychology and A.I. Beyond the controversy surrounding these various definitions, typologies, and statuses, we will highlight how complementary they may be. The second part of this review exposes the operations realized on constraints, emphasizing the three operations that were distinguished in A.I. and psychology: formulation, propagation, and satisfaction. We define these operations according to the A.I. approach, and emphasize their psychological implications. Then we present the two most studied operations in psychology: relaxation and elimination of constraints. We conclude this article by suggesting three ways of research about the role of constraints in problem solving : (1) relationships between constraints and complexity, (2) relationships between constraints and difficulty, and (3) relationships between constraints and attention processes.
• DownloadCegarra, J., & Hoc, J.-M. (2006). Cognitive styles as an explanation of expert individual differences: A case study in computer-assisted troubleshooting diagnosis. International Journal of Human-Computer Studies, 64, 123-136. AbstractAbstract: Individual differences are a crucial aspect of field studies because of the consequences they can have on performance. However, in Cognitive Ergonomics, individual differences have mainly been interpreted as expertise effects. As can be noted from the literature, this limitation has led to difficulties in explaining differences between experts. Using a case study which identifies significant variations between expert performances [Jouglet, D., Piechowiak, S., Vanderhaegen, F., 2003. A shared workspace to support man-machine reasoning: application to cooperative distant diagnosis. Cognition, Technology & Work 5, 127-139], we attempt to go beyond the traditional approach based on expertise levels. Instead, we refer to the notion of cognitive styles. First, we consider methodological issues raised by a posteriori identification of cognitive styles within this diagnosis task. Second, we present the results of our analysis showing that individual differences are related to a particular dimension of cognitive style in which a balance between task requirements and cognitive resources is managed. Finally, we draw conclusions on the importance of cognitive styles in Cognitive Ergonomics.
• Chevalier, A., & Cegarra, J. (2006). A constraint satisfaction approach to study the management of multiple objectives in design problem-solving. Psychological Reports, 99, 488-493.
• DownloadHoc J.-M., Mebarki N., & Cegarra, J. (2004). L'assistance à l'opérateur humain pour l'ordonnancement dans les ateliers manufacturiers [Human operator support of scheduling in manufacturing workshops]. Le Travail Humain, 67, 181-208. AbstractRésumé : Ce texte présente d'abord les différentes situations d'ordonnancement et les questions qu'elles posent, tant aux machines qu'aux humains. Il fait ensuite le point sur les travaux menés depuis la dernière revue de question exhaustive de P. Sanderson (1989) sur les facteurs humains dans l'ordonnancement. Il rappelle l'état de la question en 1989 et décrit quelques avancées dans le renouvellement des approches formelles, dans l'analyse des stratégies humaines et dans l'émergence d'une conception plus coopérative des relations homme-machine dans ce domaine. Il se conclut par quelques directions de recherche qui pourraient être prometteuses.
  
  Abstract: At first, this paper presents three scheduling situations from a technical point of view. First, static scheduling is considered as designing a schedule before the execution. Second, dynamic scheduling considers the elements of the problem in real time, as they are known. Third, reactive scheduling consists in modifying a schedule on the basis of unexpected events. The questions raised in these situations for machines, but mainly for humans are formulated. How do humans reduce complexity? How do they manage uncertainty? What is the nature of human expertise? What is the human role in the scheduling process? What degree of confidence should the human have in the machine's model of the problem? Is the human able to improve the solution provided by the machine? What kind of diagnosis is necessary when deciding and implementing a modification in a schedule? Then, the paper tries to find some replies to these questions in the literature. At first, it sums up the state of the art published by P. Sanderson in 1989 on human factors in scheduling. Three main contributions were prevalent during this period. First, the comparison between human strategies and simple scheduling rules showed the frequent superiority of the former over the latter. Second, hybrid systems (human-machine cooperation) were designed and evaluated as better than humans or machines alone. Third, human-computer interfaces were evaluated, integrating prediction and graphical features. A limitation of these studies was their poor ecological validity, as they were restricted to laboratory settings. The paper describes some progress in the renewal of these approaches. Individual protocol analysis gave a more precise access to human strategies. Formal approaches were enriched with contributions from distributed cognition. Some progress has been done in the analysis of human-computer interfaces developed within the context of ecological interfaces. Finally a cooperative conception of the human-machine relationships grew in the domain, as well as a search for supporting human machine cooperation in distributed scheduling. The paper concludes on some research directions that could be promising to reach a better understanding of human strategies and representations, to design more efficient human-machine interfaces and cooperation, and to devote more consideration to dynamic and reactive scheduling.

Proceedings or book chapters

• Cegarra, J., Dehais, F., Causse, M, & Martin, C. (2011). L'ergonomie dans l'aéronautique. In J. Dinet & C. Bastien (Eds.), L'ergonomie des objets et environnements physiques et numériques (chapitre 7). Hermès Lavoisier.
• Cegarra, J., & VanWezel, V. (2010). A comparison of task analysis methods for planning and scheduling. In J. Fransoo, T. Waefler, & J.R. Wilson (Eds.), Behavioral Operations in Planning and Scheduling (pp.323-338). Berlin: Springer.
• Riedel, R., Fransoo, J, Wiers, V., Fischer, K., Cegarra, J., & Jentsch, D. (2010). Building Decision Support Systems for Acceptance. In J. Fransoo, T. Waefler, & J.R. Wilson (Eds.), Behavioral Operations in Planning and Scheduling (pp.231-298). Berlin: Springer.
• Van Wezel., V., Cegarra, J., & Hoc, J.-M. (2010). Allocating Functions to Human and Algorithm in Scheduling. In J. Fransoo, T. Waefler, & J.R. Wilson (Eds.), Behavioral Operations in Planning and Scheduling (pp.339-370). Berlin: Springer.
• Gacias, B., Cegarra, J., & Lopez, P. (2009). An interdisciplinary method for a generic vehicle routing problem decision support system. Proceedings of the International Conference on Industrial Engineering and Systems Management (IESM'2009).
• Cegarra, J. (2008). Psychologie différentielle et psychologie ergonomique : des points de vue à réconcilier ? In Loarer, E. (Ed.), La psychologie différentielle et ses applications (pp. 543-546). Rennes : P.U.R.
• DownloadCegarra, J., & Hoc, J.-M. (2006). The role of algorithm comprehensibility on complacency in automated scheduling. In Pikaar, R.N., Koningsveld, E.A.P., & Settels, P.J.M. (Eds.), Proceedings of the 16th World Congress on Ergonomics (International Ergonomics Association'06) (pp. 1903-1908). Maastricth, The Netherlands: Elsevier. AbstractAbstract: Several authors have identified the existence of complacency in supervision tasks which imply automation or computer support (such as airline piloting). These studies have stressed that even expert operators who are aware of a machine's limits could adopt its proposals without questioning them. In scheduling situations (for example, train timetable generation), this is a significant problem, as it is often suggested that the machine be allowed to build the schedule, confining the human role to that of rescheduling. In order to reduce complacency in scheduling one could offer several solutions from among which the human scheduler could choose one: however, this could create difficulties because of the complexity of this particular task. In this article, we suggest that scheduling algorithms be characterized as having different levels of algorithm comprehensibility (i.e. different levels of complexity). The effect of this characteristic was evaluated on human rescheduling performance, the quality of which was related to complacency. Our findings stress that algorithm comprehensibility leads to poor performance due to the very high cost of understanding the algorithm.
• Cegarra, J., & Chevalier, A. (2007). Theoretical and methodological considerations in the comparison of performance and physiological measures of mental workload. Lectures Notes in Artificial Intelligence, 4562 (pp. 264-268). Berlin: Springer.
• van Wezel, W., & Cegarra, J. (2006). A task allocation model for planning. In Pikaar, R.N., Koningsveld, E.A.P., & Settels, P.J.M. (Eds.), Proceedings of the 16th World Congress on Ergonomics (International Ergonomics Association'06) (pp. 1897-1902). Maastricth, The Netherlands: Elsevier
• Cegarra, J. (2005). Effet de « contentement » dans la coopération Homme-machine en ordonnancement. In É. Raufaste & A. Tricot (Eds.), Actes des 3èmes Journées d'étude en psychologie ergonomique (EPIQUE'05) (pp. 107-113), Toulouse, France : Presses de l'université Toulouse le Mirail.
• Cegarra, J., & Hoc, J.-M. (2003). From Human Heuristics to the Design of Scheduling Interfaces. Proceedings of the 1st Multidisciplinary International Conference on Scheduling: Theory and Applications (pp. 236-239), Nottingham, UK: The University of Nottingham.
• Cegarra, J., & Hoc, J.-M. (2003). Human Scheduling and its Support. Adjunct Proceedings of the Human Computer Interaction International 2003 (pp. 173-174), Heraklion: Crete University Press.
• Cegarra, J., & Hoc, J.-M. (2003). Individual differences and distributed cognition: the case of troubleshooting diagnosis. In G.C. van der Veer & J.F. Hoorn (Eds.), Proceedings of Cognitive Science Approaches to Process Control'03 (pp. 113-118), Amsterdam, The Netherlands: EACE.

Conferences

• Martin, C., Cegarra, J., & Averty, P. (2011). Analysis of Mental Workload during En-route Air Traffic Control Task Execution based on Eye-Tracking Technique. Communication presented at the 14th International Conference on Human-Computer Interaction (HCI’2011), Orlando, USA.
• Gacias, B., Lopez, P., & Cegarra, J. (2010, June). Work domain analysis and ecological interface for the vehicle routing problem. Communication presented at the 11th IFAC/IFIP/IFORS/IEA Symposium on Analysis, Design, and Evaluation of Human-Machine Systems. Valenciennes, France.
• Gacias, B., Lopez, P., & Cegarra, J. (2010, May). A decision support system for vehicle routing based on model inversion and data analysis. Communication presented at the 8th International Conference of Modeling and Simulation (MOSIM'10). May 10-12, 2010, Hammamet, Tunisia.
• Valax, M.-F., Baracat, B., Cegarra, J., & Rattat, A.-C. (2009, September). Prospective Memory time-based: Effects of daylight saving time on the memory of appointments. The European Society for Cognitive Psychology – XVI Conference, Krakow.
• Cegarra, J., & Morgado, N. (2009, Septembre). Étude des propriétés de la version francophone du NASA-TLX. Communication présentée à la cinquième édition du colloque de psychologie ergonomique (Epique), Nice, France.
• Gacias, B., Cegarra, J., & Lopez, P. (2009, Mars). Analyse du domaine de travail pour les problèmes de tournées de véhicules. Communication présentée aux 3èmes Journées Doctorales du GDR MACS (JDMACS 2009), Angers, France.
• Gacias, B., Lopez, P., & Cegarra, J. (2008, September). A work domain analysis for the Vehicle Routing Problem. Communication presented at the 1st Human and Organisational Factors in Planning and Scheduling Conference, Lausanne, Suisse.
• Cegarra, J., Rattat, A.-C., & Valax, M.-F. (2008, Septembre). Quelles sont les ressources sous-jacentes aux estimations de durées écoulées ? Communication affichée au Congrès de la Société Française de Psychologie, Bordeaux, France.
• Cegarra, J., Rattat, A.-C., & Valax, M.-F. (2008, Juillet). Estimer la durée d’une tâche par une barre de progression : horloge interne ou représentation spatiale ? Communication orale à la 14ème Journée d'Étude sur le Traitement Cognitif des Systèmes d'Information Complexes, Toulouse, France.
• Cegarra, J. (2007, Septembre). Réduction de la complexité dans la planification des transports. Une étude de l'élaboration de tournées de véhicules. Communication présentée aux 4èmes Journées d'étude en psychologie ergonomique (EPIQUE'07), Nantes, France.
• Cegarra, J., & Chevalier, A. (2007, july). Theoretical and methodological considerations in the comparison of performance and physiological measures of mental workload. Communication presented at the 12th International Conference on Human-Computer Interaction (HCI'07), Beijing, China
• Fransoo, J., Riedel, R., Wiers, V., & Cegarra, J. (2007, July). Trust in Decision Support Systems - conceptual model and empirical insights to foster acceptance and usage. Communication presented at the 11th International Conference on Human Aspects of Advanced Manufacturing Agility and Hybrid Automation (HAAMAHA'07), Poznan, Poland
• van Wezel, W., & Cegarra, J. (2007, June). Developing user-oriented scheduling algorithms. Communication presented at the 14th International Annual EurOMA Conference, Ankara, Turkey
• Cegarra, J. (2006, Septembre). Les apports de la psychologie différentielle aux études de psychologie ergonomique. Communication présentée aux XVIIèmes Journées de Psychologie Différentielle, Nanterre, France.
• Cegarra, J., & Hoc, J.-M. (2005, Septembre). Différences inter-individuelles entre opérateurs experts : Apport des styles cognitifs aux études de Psychologie Ergonomique. Congrès de la Société Française de Psychologie, Nancy, France.
• Cegarra, J., & Van Wezel, W. (2005, Juin). Function allocation in scheduling: Using a cognitive typology to design algorithmic support for scheduling subtasks. Communication présentée au 7th International Workshop on Human Factors in Planning, Scheduling and Control in Manufacturing, Groningen, Pays-Bas.
• Cegarra, J., & Hoc, J.-M. (2004, Juin). A Cognitive Ergonomics Approach to Scheduling Algorithm Selection. Communication presented at the 6th International Workshop on Human Factors in Planning, Scheduling and Control in Manufacturing, Jönköping, Suède.
• Chevalier, A., Kicka, M., & Cegarra, J. (2004, Juin). Quels sont les effets de la qualité ergonomique d'un site web et de l'expérience des utilisateurs sur la charge cognitive et le temps de navigation ? Communication présentée à la 9ème Journée d'Étude sur le Traitement Cognitif des Systèmes d'Information Complexes, Genève, Suisse.
• Cegarra, J., & Mebarki, N. (2002, Décembre). Les compétences humaines de ré-ordonnancement. Communication présentée au 1er Colloque Gestion des Compétences et des Connaissances en Génie Industriel, Nantes, France.
• Cegarra, J. (2002, Juin). Stratégies de diagnostic et complexité de la situation : le cas des dérangements téléphoniques. Communication présentée à la 8ème Journée d'Étude sur le Traitement Cognitif des Systèmes d'Information Complexes, Brest, France.
• Cegarra, J., & Hoc, J.-M. (2003, Septembre). La gestion des objectifs multiples et contradictoires en ordonnancement. Communication affichée au Congrès de la Société Française de Psychologie, Poitiers, France.

Invited conferences

• Hoc J.-M., Cegarra, J., & Mebarki, N. (2005, Juin). Human operator support within the context of scheduling. Communication invitée au 7th International Workshop on Human Factors in Planning, Scheduling and Control in Manufacturing, Groningen, Pays-Bas.

Internationals seminars

• Chevalier, A., & Cegarra, J. (2006, September). Towards theoretical and methodological improvements of cognitive load study: the combination of measures. Communication présentée au Workshop Cognitive Load Measure and Cognitive Processing of Documents, Toulouse, France.
• Van Wezel, W., & Cegarra, J. (2006, March). A review of the applicability of task analysis and function allocation approaches for planning and scheduling. Communication présentée au COST A29 " HOPS " seminar, Prague.
• Cegarra, J., Mebarki, N., & Hoc, J.-M. (2005, October). Modelling scheduling in relation to design of human-machine cooperation. Communication présentée au COST A29 " HOPS " seminar, Malte.
• Van Wezel, W., & Cegarra, J. (2005, October). Using a cognitive typology to design algorithmic support for scheduling subtasks. Communication présentée au COST A29 " HOPS " seminar, Malte.
• Hoc J.-M., Cegarra, J., & Mebarki, N. (2005, March). From human strategies to the design of Human-machine cooperation in scheduling: Past, current and future projects at IRCCyN. Communication présentée au 1st COST A29 " HOPS " Management Committee Meeting, Montreux, Suisse.
• Cegarra, J., & Hoc, J.-M. (2003, September). Understanding Human Scheduling. Séminaire commun Université de Groningen & IRCCyN, Groningen, The Netherlands.

Other

• Download (Warning: the file size is about 5Mo!)Cegarra, J. (2004). La gestion de la complexité dans la planification : le cas de l'ordonnancement [The management of complexity in planning: the case of scheduling situations]. Ph.D Thesis, University of Paris 8, France.