The use of the Web to deliver open, distance, and flexible learning has opened up the potential for social interaction and adaptive learning, but the usability, expressivity, and interoperability of the available tools leave much to be desired. This article explores these issues as they relate to teachers and learning designers through the case of…

Distance and blended collaborative learning settings are usually characterized by different "social structures" defined in terms of groups' number, dimension, and composition; these structures are variable and can change within the same activity. This variability poses additional complexity to instructional designers, when they are…