Longitudinal Evaluation of API Usability and Designing Support for Collaborative Search around the Tabletop

In this talk, I’d like to present two very diverse topics: API usability evaluation and collaborative faceted search around the tabletop.

First, I will present the Concept Maps method as a longitudinal evaluation and assessment method to elicit the programmer’s mental model of an API. Application programming interfaces (APIs) are the interfaces to existing code structures, such as widgets, frameworks, or toolkits. Therefore, they very much do have an impact on the quality of the resulting system. The Concept Maps approach asks developers to visualize their understanding of an API by creating a concept map, showing the relationship between the API and their own code. Thereby, we can to identify misconceptions and problematic areas and by using a longitudinal study design, we can assess how these are changing over time.

In the second part, I will introduce “Facet-Streams”, a hybrid interactive surface for co-located collaborative product search on a tabletop. Facet-Streams combines techniques of information visualization with tangible and multi-touch interaction to materialize collaborative search on a tabletop. It harnesses the expressive power of facets and Boolean logic without exposing users to complex formal notations. In two user studies we were able to show how Facet-Streams unifies visual and tangible expressivity with simplicity in interaction, supports different strategies and collaboration styles, and turns product search into a fun and social experience.