SoCCR - Optimistic concurrency control for the web-based collaborative framework metafora

Abstract

In this paper we present the concurrency control used in the computer-supported collaborative learning framework Metafora. Metafora is an environment that supports complex learning scenarios utilizing multiple learning tools, such as a tool for the planning of learning activities, a graphical argumentation tool and several microworlds in the domains of science and mathematics. Since Metafora is a web-based framework, specific requirements have to be fulfilled for smooth collaboration and inter-tool communication. For smooth collaboration we will describe our optimistic concurrency control approach that allows concurrent modification of shared objects in a workspace as far as possible. While move and edit actions can be performed in parallel, a Social Concurrency Conflict Resolution (SoCCR) protocol enables collaborative editing of text nodes in the planning space. We will illustrate this with an example of user interaction in the Metafora system involving the concurrency mechanism. © 2012 Springer-Verlag.