This paper reports on a case-study design experiment in the domain of fraction as number-measure. We designed and implemented a set of exploratory tasks concerning comparison and ordering of fractions as well as operations with fractions. Two groups of 12-year-old students worked collaboratively using paper and pencil as well as a specially…

Arguably the biggest "buzz word" of the current year has been "learning or knowledge object". To understand the learning object and why it should be such a highly desirable commodity, it is necessary to unpack not only this concept but more importantly revisit some contributing concepts and constructs (more buzz words) that support the building of…

Computer-based learning environments commonly comprise symbolic as well as static and dynamic pictorial representations, frequently combined with the possibility of modifying them interactively. While multiple, dynamic and interactive external representations have the potential to improve learning in various ways, they also place specific demands…