Eye tracking scanpaths contain information about how people see, but traditional tangled, overlapping scanpath representations provide little insight about scanning strategies. The present work describes and extends several compact visual scanpath representations that can provide additional insight about individual and aggregate/multiple scanning strategies. Three categories of representations are introduced: (1) Scaled traces are small images of scanpaths as connected saccades, allowing the comparison of relative fixation densities and distributions of saccades. (2) Time expansions, substituting ordinal position for either the scanpath's x or y-coordinates, can uncover otherwise subtle horizontal or vertical reversals in visual scanning. (3) Radial plots represent scanpaths as a set of radial arms about an origin, with each arm representing saccade counts or lengths within a binned set of absolute or relative angles. Radial plots can convey useful shape characteristics of scanpaths, and can provide a basis for new metrics. Nine different prototype scanning strategies were represented by these plots, then heuristics were developed to classify the major strategies. The heuristics were subsequently applied to real scanpath data, to identify strategy trends. Future work will further automate the identification of scanning strategies to provide researchers with a tool to uncover and diagnose scanning-related challenges.

Eye tracking specialists often need to understand and represent aggregate scanning strategies, but methods to identify similar scanpaths and aggregate multiple scanpaths have been elusive. A new method is proposed here to identify scanning strategies by aggregating groups of matching scanpaths automatically. A dataset of scanpaths is first converted to sequences of viewed area names, which are then represented in a dotplot. Matching sequences in the dotplot are found with linear regressions, and then used to cluster the scanpaths hierarchically. Aggregate scanning strategies are generated for each cluster and presented in an interactive dendrogram. While the clustering and aggregation method works in a bottom-up fashion, based on pair-wise matches, a top-down extension is also described, in which a scanning strategy is first input by cursor gesture, then matched against the dataset. The ability to discover both bottom-up and top-down strategy matches provides a powerful tool for scanpath analysis, and for understanding group scanning strategies.

Liquid layout of web browser elements enables enterprise applications to adapt to larger windows on larger displays, but guidelines are needed to define layout rules for widescreen page content. The present study considers the impact of relative portlet distance and orientation in enterprise-type tasks. Eighteen analysts completed tasks in which critical information was located in two portlets separated by defined distances and orientations. Analysis of completion times, assists, errors, and subjective scales revealed a significant advantage for wider, horizontal information layouts over narrower, vertical layouts. The difference persisted, even when accounting for the influence of vertical scrolling. Horizontal layout in these dashboard-style tasks had a 5%-25% time savings over vertical layout, as separation distances increased to 2000 pixels. Differences in horizontal and vertical eye movement accuracy and velocity could account for these results. Widescreen design guidelines should include a preference for horizontal layout as horizontal screen distances increase.

Plasma Posters are large screen, digital, interactive poster-boards situated in public spaces, designed to facilitate informal content sharing within teams, groups, organizations and communities. While interest i interactive community poster boards has grown recently, few successful examples have been reported. In this paper we describe an ongoing installation of Plasma Posters within our organization, and report qualitative and quantitative data from 20 months of use showing the Posters have become an integral part of information sharing, complementing email and Web-based sharing. Success factors include our design process, the reliability and flexibility of the technology and the social setting of our organization. We briefly describe three external installations of the Plasma Poster Network in public places. We then reflect on content posting as "information staging" and the ways in which the public space itself becomes part of the "interface" to content.

In this paper, we describe the YeTi information sharing system that has been designed to foster community building through informal digital content sharing. The YeTi system is a general information parsing, hosting and distribution infrastructure, with interfaces designed for individual and public content reading. In this paper we describe the YeTi public display interface, with a particular focus on tools we have designed to provide lightweight awareness of others' interactions with posted content. Our tools augment content with metadata that reflect people's reading of content - captured video clips of who's reading and interacting with content, tools to allow people to leave explicit freehand annotations about content, and a visualization of the content access history to show when content is interacted with. Results from an initial evaluation are presented and discussed.

We demonstrate the use of detail-on-demand hypervideo in interactive training and video summarization. Detail-on-demand video allows viewers to watch short video segments and to follow hyperlinks to see additional detail. The player for detail-on-demand video displays keyframes indicating what links are available at each point in the video. The Hyper-Hitchcock authoring tool helps users create hypervideo by automatically dividing video into clips that can be combined in a direct manipulation interface. Clips can be grouped into composites and hyperlinks can be placed between clips and composites. A summarization algorithm creates multi-level hypervideo summaries from linear video by automatically selecting clips and placing links between them.

No abstract available.

An experimental graphical control specification system, called Panther, has been written in C for UNIX®-based applications. Unlike similar systems, which focus on combining interaction techniques, Panther allows the specification of low-level interactions by invoking user-selectable subroutines for input-device transitions. A Panther interface is specified in a textual table as a set of hierarchically nested regions. Regions can model any control device, such as menu buttons, slider-bars, switches, alphanumeric displays, or even combinations of other regions. Panther does not rely on special hardware, extensive software, or interprocess communication.