Users engaged in information search often reformulate or modify their queries. This paper reports on an investigation of how task type and task situation influence users’ query reformulation behavior. A controlled experiment was conducted with 48 participants, each working on six web search tasks classified into three types according to the task structure: Simple, Hierarchical and Parallel. We ...

Researchers typically use incentives (such as money or course credit) in order to obtain participants who engage in the specific behaviors of interest to the researcher. There is, however, little understanding or agreement on the effects of different types and levels of incentives used. Some results in the domain of statistical reasoning suggest that performance differences — previously deemed ...

In the 2006 competition workshop held at Dagstuhl, Germany, there were many fruitful discussions about the difficulties facing computer science competitions today. Our competitions have several purposes: to foster interest in the discipline, to create a community, and to promote achievement, for example. Balancing these various purposes may require many tradeoffs. Several participants identifie...

This article reports on results from a design research project that implements formative assessment practice with support classroom response system (CRS). Cumulatively building earlier and drawing iteratively generated data secondary schools in Sweden, the elaborates principles task types for constructing CRS tasks aimed at generating mathematical discussions. The study three principles, six 31...