The Accuracy of Online Street Maps

Posted: August 30th, 2006 | No Comments »

In How Accurate are Online Street Maps?, Cartography provides examples of spatial uncertainty due to location presentation.

 Blogger 2332 1061 1600 Google.8  Blogger 2332 1061 1600 Yahoo.0  Blogger 2332 1061 1600 Msnmaps  Blogger 2332 1061 1600 Map24  Blogger 2332 1061 1600 Randmcnally  Blogger 2332 1061 1600 Mapquest  Blogger 2332 1061 1600 Teleatlas  Blogger 2332 1061 1600 City

Relation to my thesis: Real-life example of spatial uncertainty in online mapping systems due to a tolerance in the location presentation.


In Rainy Paris

Posted: August 29th, 2006 | 2 Comments »

Paris Cable Ratp Paris Pietons Signe Paris Map Reading


INSEAD, Fontainebleau

Posted: August 28th, 2006 | No Comments »

Serious game meeting at INSEAD, Fontainebleau
Umbrelas Insead Clock Insead


Analyse et Modélisation des Activités Coopérative Situées

Posted: August 26th, 2006 | No Comments »

Salembier, P. & Pavard, B. (2004) Analyse et modélisation des activités coopératives situées. Evolutions d’un questionnement et apports à la conception, @CTIVITES, n°1, Vol.

Cet article retrace les évolutions d’un programme de recherche centré sur l’analyse, la modélisation et l’instrumentation des activités coopératives. Dans son fil conducteur, il introduit plusieurs points (explication des arrière-plan théoriques, méthodes d’appréhension des objects théoriques ciblés, nature des modèles produits, rapport à la conception des situations) important à considérer lors de la réflexion générale sur l’édute des activités professionnelles, collectives et coopératives. Les auteurs pointent les avantages et les limites de différent orientations théoriques et méthodologiques ayant balisé leur travail.

Mentions sont faites des différentes conceptions de la cooperation homme-machines. Une première orientation illusior et l’approche mimétique dans laquelle la reproduction des caractéristiques des situations de coopération homme-homme se heurte à des limitations technologiques, mais également à des problèmes de font qui ont trait à la non reconnaissance de la profonde asymétrie des partenaires . Ceci est en fait le thème de “Plans and Situated Actions” de Lucy Schuman. Une alternative est “l’allocation de fonction“, c’est-à-dire procéder à la répartition des tâches entre opérateur et système (MABA-MABA: “Men are Better At – Machines Are Better At”). Cette approche a donné lieu à des recherches autour de la notion de “système cognitif joint” où l’artifact informatique tient un rôle d’”outile congnitif“. Une approche pragmatique est l’ingénieurie cognitive qui fait appelle à la “Triade du système cognitif” (Woods, 1998) avec ces trois facteurs: le monde, l’agent (humaine, machine, système “hybride”) qui opère sur les monde et les instances de méditisation du réel. L’idée sous-jacente est que la concéption de supports améliorant l’éfficacité de la réalisation de la tâche passe nécessairement par la compréhension des interactions entre ces trois éléments. Les exigences et contraintes sont pris en compte lors de la construction d’une description cognitive autonome de l’environnement (facteurs augmantant la complexités cognitive de la tâche tels que la nature dynamique de l’environnement, nombre important de parties interconnectées, incertitude des données, ..). Tout déséquilibre de la Triade risque de se traduire par l’émergence d’une situation dangereuse ou non désirée doit alors faire l’objet d’une réponse adaptée. Les méthodes utilisées pour mener à bien le processus de mise en relation systématique entre exigences de la tâche, contraintes imposées par l’environnement et ressources cognitives mobilisables par l’agent, ont été synthétisées sous le terme de “Cognitive Task Analysis“. Le point important est que les situations sont spécifiées en terme cognitifs et non pas comme en ingénieurie classique dans les termes du dispositif technique. Le rôle de cette analyse de l’activité permet d’identifier les bottlenecks dans le système, c’est-à-dire les limitations cognitives dans le couplage opérateur-outil et les contraintes de l’environnement pointées par les opérateur.

Référentiel contextuel
Les auteurs se sont alors centrés sur les mécanismmes informels de la coopération homme-homme, plus précisement sur la construction et l’actualisation dans le cours de l’activité d’un référentiel contextuel partagé qui constitue une des conditions du déploiement efficace de l’activité collective dans un environnement complexe distribué et la régulation par ce collectif de facteurs tels que les variations dans la charge de travail et la fiablilité globale du système socio-technique.

Rôle des artefacts
Les premières analyses sont restés très superficielles quant aux propritétés physiques des objects utilisés par les opérateur. Les objet étaient essentiellement considérés dans leur dimension informationnelles (artefacts cognitifs) et non dans leur dimension manipulable (constituvité matérielle des activités cognitives)

Modélisation et simulation
La construcction de modèles n’est pas jugée nécessaire voire utile par les ethnométhodologue. Les auteurs ont tout d’abord utilisé la modélisation pour décrire et non simuler. Puis ils ont recouru à la simulation:

L’idée est ici plutôt de jouer sur un ensemble de variables exogènes d’environnement pour explorer un changement de situation (introduction d’un nouvel outil, modifications des formes d’organisation du collectif, …) et évaluer son impact sur des variables endogènes jugées pertinentes -par exemple une appréciation quantitative du contexte partagé- (Zorola-Villarreal, Pavard, & Bastide, 1995 ; Salembier, Kahn, Zorola-Villarreal, & Zouinar, 1997). La simulation fonctionne comme un moyen pour « ouvrir l’espace de conception » et nourrir l’interaction (discussion et négociation) entre les acteurs engagés dans la conception autour de différentes alternatives possibles.

Les auteurs vont alors passés des outils logiques classiquement utilisés en sciences cognitive aux théories de la complexité et aux systèmes dynamiques non linéaires. La raison qui movitve ce choix tient à l’acceptation du fait que la dynamique des processus qui supportent la coopération sont la plupart du temps impossilbe à prévoir car non déterministes du fait notamment de leur caractère distribué et de leur sensibilité aux vations environnementales. (Pavard & Dugdale, 2000).

La démarche mise en oeuvre se résume à: analyse de la tâche, analyse de l’activité, simulation papier-crayon, simulation partielle de la situation, mise en situation recréée, simulation informatique.

Limites
Les limites de l’approche sur la modélisation multi-agent est se concentrer essentiellement sur l’émergence de propriétés globales sans pouvoir les articuler avec les comportements locaux des agents ; le spectre d’un collectivisme méthodologique radical n’est pas loin… De plus, la dimension « située » des acteurs, leurs connaissances culturelles, leur intelligence contextuelle, … sont des dimensions difficiles sinon impossibles à représenter de façon synthétique dans les agents distribués (Dugdale & Pavard, 2002).

Dans la suite de l’étude, les outils utilisés sont essentiellement des environnements de simulation multi-agents qui permettent de recréer la dynamique du fonctionnement du collectif en réponse à des modifications de l’environnement externe (survenue d’événements particuliers) ou interne (modification de la structure du collectif d’agents).

Relation to my thesis: Je m’étais éloingné des aspects collectifs et coopératif de l’utilisation d’applications géolocalisées et de leur étude en situation “naturelle” ainsi que de l’utilisation d’ABM. Dans leurs études, Salembier et Pavard utilisent la simulation comme un moyen pour « ouvrir l’espace de conception » et nourrir l’interaction (discussion et négociation) entre les acteurs engagés dans la conception autour de différentes alternatives possibles. Ils ont fait appel à des champs disciplinaires connexes (théorie des actes de langage, théorie des systèmes complexes, éthologie, théorie des systèmes multi-agents, interactionnisme, …).


Thema Chronos: Moi@Ici&Maintenant

Posted: August 26th, 2006 | No Comments »

Le Thema Chronos du 16 mai 2006 aborde les questions qui anime ma recherche. C’est-à-dire “quelles informations ai-je besoin, ai-je envie pour evoluer dans l’espace?”, “quelles sont leurs modalités d’accès et leur économie?” et “comment atteindre la précision nécessaire pour une information contextualisé, localisée, personalisée?”. Mention est également fait du cadre temporel de la mobilité et de l’information.


Discerning Context Through Reinforcement Learning

Posted: August 26th, 2006 | No Comments »

Santiago, Roberto A., George G. Lendaris (2005), “Discerning Context Through Reinforcement Learning,” Proceedings of the American Association of Artificial Intelligence Conference 2005 (AAAI’05), Pittsburgh, Pennsylvania, July. Submitted

This paper presents a method for using reinforcement learning (RL) to construct an artificial agent capable of applying learning knowledge in a contextually appropriate way (Contextual Reinforcement Learning). In the proposed method, the stream of inputs and feedback used by the machine learning algorithm is treated as a context to the optimal parameters as determined by the algorithm. Thus, each set of parameters has a context in which they are most appropriate. The reinforcement learning aspect of the method seeks to build an algorithm which works across contexts and extracts those features which are most informative about the optimal parameter settings. Thus for novel context, the proposed methods works to extract context features and translate them into an “educated guess” of the appropriate parameter settings.

Relation to my thesis: This paper was one inspiration for my doctoral school paper on Improving Location-Aware Applications Through Reinforcement Learning. I find machine learning interesting because it could give a sense of evolution of the system according to its usage and environment. Interaction is not only done via an interface, the core of a context-aware application could co-evolve with the user.


Towards Realizing Global Scalability in Context-Aware Systems

Posted: August 25th, 2006 | No Comments »

Buchholz, T., Linnhoff–Popien, C., Towards Realizing Global Scalability in Context–Aware Systems In Location- and Context-Awareness. Proceedings of the First International Workshop, LoCA 2005, Lecture Notes in Computer Science (3479), pages 26-39, Springer, Oberpfaffenhofen, Germany, Mai, 2005.

Most of research in ubiquitous computing focus on application where all entities involved in a user session are located in each other’s spatial proximity. This has been coined as “localized scalability”. However there are application where the users are not collocated. Thus, interactions between distant entities are needed. In these situation arise the question of how global scalability in context-aware systems can be reached. This paper classifies Context-Aware Services (CASs) according to their scalability needs and reviews context provision and service provision infrastructure with regard to their scalability.

Buchholz Scalability

Scale consists of a numerical (number of users, context sources), a geographical (distance between the farthest nodes), and an administrative dimension (number of organizations). A system is scalable if users, objects and services can be added, if it can be scattered over a larger area, it if the chain of value creation can be divided among more organizations without the system suffering loss of performance or increased administrative complexity. Scalability problems arise especially if dynamic properties of target object (target context) and of objects between the user’s current position and the targets’ position (transition context) are included into the recommendation given to the user.

Buchholz Classification Context Provision

Good candidates as a suitable CAS provision infrastructure are grids, P2P networks, and CDNs. These systems need to be coupled with a large-scale context provision infrastructure (providing homogeneous access interface of context information).

Relation to my thesis: As I am at applying ubiquity in the real-world, I am interested in the scalability of ubiquitous technologies. This papers the properties to scale from local towards global.


Everyday Encounters with Context-Aware Computing in a Campus Environment

Posted: August 25th, 2006 | No Comments »

Barkhuus, Louise and Paul Dourish, “Everyday Encounters with Context-Aware Computing in a Campus Environment“. In Proceedings of UbiComp 2004, Nottingham, UK, 2004.

This paper report on a field work which highlights that in heterogeneous groups, concerns such as location infrastructure, access and mobility can take on quite different forms, with very different implications for technology design and use. Context-aware computing attemps to make the context in which technologies are deployed and used into a configuration parameter for those technologies. In this paper, the authors consider context of a rather different sort – the social, organizational, and institutional contexts into which context-aware and ubiquitous technologies are deployed. They take the “embodied interaction” approach of ubicomp, that is moving the focus from the technology itself to the settings within which that technology will be employed. In their empirical investigation of the use of ubiquitous computing blending mobile and location-based technologies to create augmented experiences for university students (UCSD Active Campus project), they focuses on how the technology fits into broader social context of student life. They examined the factors that influence adoption and use of ubiquitous computing technologies and studies the emergent practices of ubiquitous computing (i.e. collective practices that emerge when a technology is put into the hands of an active user community)

The study revealed five concerns for the design of effective ubiquitous computing experiences at a large-scale:

  • Technology design must be sensitive to the variability of institutional arrangements. That is that technology use is systematically related to people’s roles and relationships.
  • Different temporal dynamics apply to laboratory settings and real-world settings. In real-world setting, new technologies must live along side old ones
  • We must be attentive to infrastructure of all sorts (both technological and procedural infrastructures).
  • Look at the relationship between technology and local cultural practices.
  • Technologies are a means by which relationships between social groups are enacted.

Relation to my thesis: the move of ubiquitous computing from laboratory settings into the everyday world (in the trend of Abowd’s everyday computing). Barkhuus and Dourish show an example how observational and qualitative methods can offer a set of concepts to help for the design of ubiquitous environments. The five concerns mention are an inspiration for a paper on the design and deployment of CatchBob!

Valuable references include:

W. K. Edwards, V. Bellotti, A. K. Dey, and M. W. Newman. The challenges of user-centered design and evaluation for infrastructure. In Proceedings of CHI 2003, pages 297–304. ACM Press, 2003.

J. Scott and M. Hazas. User-friendly surveying techniques for location-aware systems. In Proceedings of UbiComp 2003, pages 44–53. Springer, 2003.


Architecture of a Large-scale Location Service

Posted: August 25th, 2006 | No Comments »

Leonhardi, A. and Rothermel, K. 2002. Architecture of a Large-Scale Location Service. In Proceedings of the 22 Nd international Conference on Distributed Computing Systems (Icdcs’02) (July 02 – 05, 2002). ICDCS. IEEE Computer Society, Washington, DC, 465.

This paper proposes a a generic location service (LS) to manage highly dynamic location information for a large number of mobile objects. It suggests the support of multiple types of queries such as position query, range query and nearest neighborhood query, and take into consideration the accuracy of the location information. It should also hide the heterogeneity of data generated by sensor systems. In its architecture and to ensure scalability, the LS are organized in a hierarchical manner (similar to the GSM-1900). The LS is configured to cover a certain geographic area called the service area.

Basic Algorithm Ls

Relation to my thesis: A quick and easy paper that covers an IEEE approach to scalable location-aware systems. Generic location service are about heterogeneity in the sensed data, types of query, scalability (service areas), accuracy, and frequency of update message. On a similar subject (update protocols) there is A Comparison of Protocols for Updating Location Information.


From Interaction to Participation: Configuring Space through Embodied Interaction

Posted: August 25th, 2006 | No Comments »

Williams, A., Kabisch, E., and Dourish, P. (2005.) From Interaction to Participation: Configuring Space through Embodied Interaction. Proc. Intl. Conf. Ubiquitous Computing Ubicomp 2005 (Tokyo, Japan).

This paper explores the question of how will people encounter and understand ubiquitous environments (new space), and how will they interact with each each other through the augmented capabilities of ubicomp technologies of such environments (i.e. the reconfiguration of the relationship between people, objects and space). The fundamental concern is with the ways in which we encounter space not simply as a container for our actions, but as a setting within which we act (embodied nature of activity). The spatial organization of activities goes beyond simply space and action. Rather, it speaks to first the mutual configuration of arrangements of bodies, artifacts and activities, and second, the social and cultural practices by which actions are both produced and interpreted.

Traditional focus of HCI is on how people might interact with technologies. The author take an other approach on looking at how people engage with space and with each other through the technologies that are provided to them. Rather than focusing on the interaction, they focus on the participation. In the same time, we think and talk about ubiquitous computing systems with a primer focus on technologies and less on the space that those technology occupy. From their experience, the authors notes some broad observations:

  • People sought to understand the system not as a whole but in terms of the individual actions of different components
  • We currently lack of good design approaches for understanding the temporal aspects of technologies.
  • Ubiquitous computing technologies are ones through which people encounter and come to understand infrastructures. The presence or absence of infrastructure, or difference in its availability, become one of the way in which spaces are understood and navigated (e.g. the strength of a cellular telephone signal becomes an important aspect of how space is assessed and used).

Relation to my thesis: My thesis may contain a phenomenological perspective of how will people be able to make sense of computationally enhances spaces, and how will people be able to make sense of each other in the spaces. So far, I have noticed in Catchbob! the impact of a fluctuant link between the infrastructure based on ubicomp technologies and the activities due to the fluctuant network coverage and consistency (hurting (changing?) the communication) and spatial uncertainty. The infrastructure has an impact on the way we encounter space. This is Dourish’s “embodies interaction” paradigm. That is how technologies and artifacts take on meaning for their users through their embedding into systems of practice. Well, I shall read Where The Action Is: The Foundations of Embodied Interaction to really grasp what embodied interaction really is.