There are currently two dominant interface types for searching and browsing large image collections: keyword-based search, and searching by overall similarity to sample images. This paper presents an alternative in which users are able to navigate explicitly along conceptual dimensions that describe the images. The interface makes use of hierarchical faceted metadata and dynamically generated query previews. A usability study, conducted with 32 art history students exploring a collection of 35,000 fine arts images, compares this approach to a standard image search interface. Despite the unfamiliarity and power of the interface (attributes which often lead to rejection of new search interfaces), the study results show that 90% of the participants preferred the meta-data approach overall, 97% said that it helped them learn more about the collection, 75% found it more flexible and 72% found it easier to use than a standard baseline system. These results indicate that that a category-based approach is a successful way to provide access to image collections.

There are currently two dominant interface types for searching and browsing large image collections: keyword-based search, and searching by overall similarity to sample images. This paper presents an alternative in which users are able to navigate explicitly along conceptual dimensions that describe the images. The interface makes use of hierarchical faceted metadata and dynamically generated query previews. A usability study, conducted with 32 art history students exploring a collection of 35,000 fine arts images, compares this approach to a standard image search interface. Despite the unfamiliarity and power of the interface (attributes which often lead to rejection of new search interfaces), the study results show that 90% of the participants preferred the metadata approach overall, 97% said that it helped them learn more about the collection, 75% found it more flexible and 72% found it easier to use than a standard baseline system. These results indicate that that a category-based approach is a successful way to provide access to image collections.

Designing a search system and interface may best be served (and executed) by scrutinizing usability studies.

The security of any computer system that is configured and operated by human beings critically depends on the information conveyed by the user interface, the decisions of the computer users, and the interpretation of their actions. We establish some starting points for reasoning about security from a user-centred point of view, by modelling a system in terms of actors and actions and introducing the concept of the subjective actor-ability state. We identify ten key principles for user interaction design in secure systems and give case studies to illustrate and justify each principle, describing real-world problems and possible solutions. We anticipate that this work will help guide the design and evaluation of secure systems.

A touchscreen can be overlaid on a tablet computer to support asymmetric two-handed interaction in which the non-preferred hand operates the touchscreen and the preferred hand uses a stylus. The result is a portable device that allows both hands to interact directly with the display, easily constructed from commonly available hardware. The method for tracking the independent motions of both hands is described. A wide variety of existing two-handed interaction techniques can be used on this platform, as well as some new ones that exploit the reconfigurability of touchscreen interfaces. Informal tests show that, when the non-preferred hand performs simple actions, users find direct manipulation on the display with both hands to be comfortable, natural, and efficient.