New forms of natural user interfaces, particularly tabletops, are now a possibility due to the staggering advances in sensing and display technology. There is an immediate need for corresponding progress on the foundational software for exploiting the potential of these new hardware products. This requires research into natural and effective gestural interaction, with careful consideration of the core facilities needed for effective and consistent use. At the same time, an exploration of real-world tabletop applications will provide a basis for studying and advancing the core functionality.

We have recently begun to see hardware support for the tabletop user interface, offering a number of new ways for humans to interact with computers. Tabletops offer great potential for face-to-face social interaction; advances in touch technology and computer graphics provide natural ways to directly manipulate virtual objects, which we can display on the tabletop surface. Such an interface has the potential to benefit a wide range of the population and it is important that we design for usability and learnability with diverse groups of people.This paper describes the design of SharePic -- a multiuser, multi-touch, gestural, collaborative digital photograph sharing application for a tabletop -- and our evaluation with both young adult and elderly user groups. We describe the guidelines we have developed for the design of tabletop interfaces for a range of adult users, including elders, and the user interface we have built based on them. Novel aspects of the interface include a design strongly influenced by the metaphor of physical photographs placed on the table with interaction techniques designed to be easy to learn and easy to remember. In our evaluation, we gave users the final task of creating a digital postcard from a collage of photographs and performed a realistic think-aloud with pairs of novice participants learning together, from a tutorial script.

We describe a visualisation tool, VlUM, designed to support users in scrutinising models of their interests, preferences and knowledge. We also describe MECUREO, a tool for building lightweight ontologies from online dictionaries. It enables a user to see a model describing both their interests and additional analogically inferred interests. We report a small qualitative evaluation of this combined system. This indicates that users were able to use the system to explore models of two hypothetical users, making use of varying levels of ontological inference.

This paper describes a system which automatically constructs an extensive ontology of computer science. This can serve as a basis for making inferences about student models and other reasoning within a teaching system. The system enables a user to select a focus concept and then see the most closely related concepts.