Carla Simone

Coordination mechanisms: towards a conceptual foundation of CSCW systems design

The paper outlines an approach to CSCW systems design based on the concept of ‘coordination mechanisms.’ The concept of coordination mechanisms has been developed as a generalization of phenomena described in empirical investigations of the use of artifacts for the purpose of coordinating cooperative activities in different work domains. On the basis of the evidence of this corpus of empirical studies, the paper outlines a theory of the use of artifacts for coordination purposes in cooperative work settings, derives a set of general requirements for computational coordination mechanisms, and sketches the architecture of Ariadne, a CSCW infrastructure for constructing and running such malleable and linkable computational coordination mechanisms.

Integrating Awareness in CooperativeApplications through the Reaction-DiffusionMetaphor

The paper discusses the notion of awarenessfrom the point of view of the design of asupportive technology. This perspectiverequires a deeper understanding of the ways andmeans people adopt to deal with awarenessinformation as well as considering theintegration of awareness tools with toolssupporting other forms of coordination. First,we suggest to consider two types of awareness:by-product awareness that is generated in thecourse of the activities people must do inorder to accomplish their cooperative tasks;and add-on awareness that is the outcome of anadditional activity, which is a neat cost forthe cooperating actors in relation to what theymust do and is discretional in that it dependson actors evaluation of the contingentsituation. Secondly, we propose areaction-diffusion metaphor to describe theawareness phenomenology and to take intoaccount the two above-mentioned types ofawareness integration. The model ofawareness derived from the metaphor makesvisible and accessible by different types ofusers a set of elemental primitives whoseflexible composition allows them to constructthe awareness mechanisms they dynamically need. These primitives are incorporated in a softwaremodule that can be used in combination withcoordinative applications for sake of promotingawareness information. The main architectureof the module is presented together with itsinteroperability with the target application;moreover, a simple example illustrates how theincorporated primitives can be used to buildawareness mechanisms.

A configurable system for the construction of adaptive virtual stores

With the recent expansion of the Internet, the interest towards electronic sales has quickly grown and many tools have been built to help vendors to set up their Web stores. These tools offer all the facilities for building the store databases and managing the order processing and secure payment transactions, but they typically do not focus on issues like the personalization of the interaction with the customers. However, Web surfers are generally heterogeneous and have different needs and preferences; moreover, the trend of marketing strategies is to pay more and more attention to the specific buyers. So, the importance of personalizing the interaction with the user and the product presentation is increasing. In this paper, we describe the architecture of a configurable virtual Web store supporting personalized hypertextual interactions with users. Our system builds a user profile by applying user modeling techniques and stereotypical information about the characteristics of customer groups; this profile is used during the interaction in order to tailor the product descriptions and the selection of items to recommend to the users needs, varying the layout of the hypertextual pages and the detail of the descriptions accordingly. Tailoring the systems behavior requires the parallel execution of several complex tasks during the interaction (e.g., identifying the users preferences, selecting the products most suited to her, dynamically generating the hypertextual pages). Therefore, we have defined a multiagent architecture where these tasks are executed by different agents, which cooperate offering specific services to each other. In our system, the domain‐dependent knowledge, concerning information about products and customer features, is declaratively represented and clearly separated from the domain‐independent components, which represent the core of the virtual store. This separation has the advantage that our architecture can be easily instantiated on several sales domains, therefore obtaining different Web stores out of a single shell. Our system is developed in a Java‐based environment and the overall architecture includes the prototype of a virtual store and the configuration tools which can be used to set up a new store on a specific sales domain.

Interoperability as a means of articulation work

The interoperability of systems to support cooperative work requires moving beyond purely technical issues; it also concerns the means and practices that users adopt to articulate their cooperative activities. Articulation has to be supported by a technology which focuses on this higher level of interoperability. This claim is motivated by observing the articulation process of users in real cooperative work practice. Based on this study, the functionality for this technology was designed to help users reconcile different handling and perspectives on shared objects in their cooperative work. The paper presents the architecture of an application infrastructure centered on the identified interoperability issues and focuses on the design of a specialized module, called reconciler, which provides the above functionality. The current state of its implementation together with identifying open research problems conclude the paper.

Supporting Different Dimensions of Adaptabilityin Workflow Modeling

This paper discusses the theme of workflow systemadaptability in relation to process modeling. Startingfrom a discussion on the role of formal constructs incooperation, the main claim is that adaptabilityinvolves different dimensions of process modeling.These dimensions concern the possibility to flexiblycombine a rich set of basic categories in order toobtain the most suitable language for modeling thetarget business process and the work practices aroundit; to take into account various levels of visibilityof the contexts of definition and use of a processmodel; and finally to allow for temporary as well aspermanent modifications of the process itself.Ariadne, a notation conceived for the above purpose,is illustrated by means of a working example.Moreover, the paper presents the main designprinciples governing Ariadnes implementation.

Adaptability of classification schemes in cooperation: what does it mean?

The overview of a set of field studies highlights how different are the scenarios on which classification schemes (CS) play a role in cooperation. In all cases, adaptability is claimed as a fundamental requirement for their usability and effective usage. What adaptability means for CS is not an easy question. The paper tries to articulate this requirement and derive implications on the design of a supportive technology.

Compositional features for promoting awareness within and across cooperative applications

The existing computational mechanisms for promoting awareness are based on Awareness Models referring to spatial metaphors. These models are mainly based on the notions of focus and nimbus which allow one to compute different measures of awareness between objects. The point made in this paper is that these approaches are focused on how awareness information is produced and perceived but not on how it affects the behavior of the objects. This aspect is relevant if one takes seriously the issue of making awareness mechanisms fully visible and accessible to the involved actors for the purpose of adaptability. We propose the reaction-diffusion metaphor in order to deal with the above requirements. The related Model of Awareness is presented, compared with the Spatial Models and illustrated by some examples.

Parallel simulation of reaction—diffusion phenomena in percolation processes a model based on cellular automata

Abstract We present a model based on cellular automata for the simulation of reaction–diffusion processes that has been applied to the percolation of pesticides in the soil. The main contribution of our approach consists of a model where chemical reactions and the movement of fluid particles in a porous medium can be explicitly described and simulated. In this paper we show how the model has been used to reproduce the process that causes release of pesticides contained in the soil after their application to crops, into water flowing through the soil and to be carried to the groundwater layer, polluting it. A parallel version of the model has been successfully implemented on Cray T3E and SGI Origin 2000 parallel computers.

A Parallel Model Based on Cellular Automata for the Simulation of Pesticide Percolation in the Soil

We present a parallel model based on Cellular Automata for the simulation of reaction-diffusion processes, that has been applied to the percolation of pesticides in the soil. The main contribution of our approach consists of a model where chemical reactions and the movement of fluid particles in a porous medium can be explicitly described and simulated. The model has been used to reproduce the process that causes pesticides, contained in the soil after their application to crops, to be released into water flowing through the soil and to be carried to the groundwater layer, polluting it. The model has been successfully implemented on Cray T3E and SGI Origin 2000 parallel computers.

Integrating Contexts to Support Coordination: TheCHAOS Project

The paper reports on the outcomes of the CHAOS project whose aim was the development of a computer-based tool for coordinating activities not organized in a structured flow of work. In CHAOS coordination is achieved by negotiating commitments within conversations. The paper illustrates the conceptual foundation on which the prototype is based and its main functionalities. The latter are organized into four logical modules that are responsible of the management of the information concerning the communication, operation, organization and linguistic contexts, respectively, in which the communication occurs. The paper presents achievements and limits of the project and positions its aims and outcomes in relation to the recent debate about the Coordinator.