Two central principles of contemporary learning science theory (Stahl, Koschmann & Suthers, 2006) are: • Student learning involves construction of meaning by the learners (constructivism). • Learning often takes place originally inter-subjectively (socio-cultural theory). For learning in the discipline of mathematics, these principles imply: • Student exploration of mathematical issues should p...

This paper focuses on the interaction patterns of learners studying in pairs who were provided with multimedia learning material. In a previous article, we reported that learning scores were higher for dyads of an ‘animations’ condition than for dyads of a ‘static pictures’ condition. Results also showed that offering a persistent display of one snapshot of each animated sequence hindered colla...

Many successful algorithms, such as Asynchronous Partial Overlay (APO), have recently been developed for cooperative distributed problem solving based on the notion of coordinated mediation. In this paper we examine the impact of different strategies for choosing mediators with respect to the complexity of distributed problem solving and the difficulty in merging decentralized solutions. We pre...

A number of algorithms have been recently proposed for distributed constraint optimization problems (DCOP). Fully decentralized examples include ADOPT [11] (search) or DPOP [12] (dynamic programming). Difficult optimization problems have been shown to require important amounts of communication when these algorithms are used (large number of small messages for ADOPT, or few but large messages fo...

Performance is one of the major concerns in a Service Oriented Architecture (SOA) environment because of the verbose XML message transmitted between the service providers and the service consumers over a network. Asynchronous messaging is widely recognized as an effective communication channel in an SOA environment where the service provider and the service consumer may be separated across the ...

Previous research has indicated that groups can benefit from the combination of face-to-face and asynchronous computer-mediated communication for conducting work. This exploratory experiment compares the effectiveness of four di~erent modes of communication for groups working on the upstream phases of sofhare development: (I) face-to-face (2) synchronous computer conferencing (3) asynchronous c...

Recently, there has been a resurgence of interest in asynchronous design techniques. Asynchronous logic provides a solution to the clock-related timing problems of synchronous systems and can offer higher performance and lower power consumption. This paper presents an approach for modeling and simulating asynchronous computer architectures using occam as a description language.

Online forums (synchronous and asynchronous) offer exciting data opportunities to analyze how people influence one another through their interactions. However, researchers must address several analytic difficulties involving the data (missing values, nested structure [messages within topics], non‐sequential messages), outcome variables (discrete outcomes, rare instances, m...