Monthly Archive for May, 2007

Greenberg, S., Gutwin, C., and Roseman, M. (1996). Semantic telepointers for groupware. In Proceedings of OzCHI’96, Sixth Australian Conference on Computer-Human Interaction, pages 54–61, Hamilton, New Zealand. IEEE Computer Society Press. [pdf]

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This paper present a seminal work on the use of telepointers in the relaxed-WYSIWIS framework. The authors lists a couple of factors that limit the use of telepointers when the shared screens are not kept identical. Their solution consists in overloading the telepointer with semantic information and/or mapping the telepointer absolute coordinates to relative coordinates to each participant’s display.

Real time groupware systems often display telepointers (multiple cursors) of all participants in the shared visual workspace. Through the simple mechanism of telepointers, participants can communicate their location, movement, and probable focus of attention within the document, and can gesture over the shared view. Yet telepointers can be improved. First, they can be applied to groupware where people’s view of the work surface differs—through viewport, object placement, or representation variation—by mapping telepointers to the underlying objects rather than to Cartesian coordinates. Second, telepointers can be overloaded with semantic information to provide participants a stronger sense of awareness of what is going on, with little consumption of screen real estate.

N. O. Bouvin, P. T. Zellweger, K. Grønbæk, and J. D. Mackinlay. Fluid annotations through open hypermedia: Using and extending emerging web standards. In Proceedings of WWW 2002, Honolulu, HI, USA, May 7-11 2002. Association for Computing Machinery. [pdf]

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This paper describe a system called Fluid Annotations that is used to annotate web pages. The authors report an extensive rationale of why they choose this particular interaction mechanism for their system. The paper contains no evaluation.

Typographic conventions such as footnotes and marginalia have long been used to place supporting information on a static page without disrupting the primary information. Computer-based documents have recently augmented these conventions with hypertext links to supporting documents. Compared to static typography, hypertext has fewer limits on the size or complexity of an annotation, but at the cost of removing the supporting information from its context on the page.

We are exploring a new technique for annotation, called Fluid Documents, which uses lightweight interactive animation to incorporate annotations in their context. Our approach initially uses the space on a page for primary information, indicating the presence of supporting material with small visual cues. When a user expresses interest in a cue, its annotation gradually expands nearby. Meanwhile, the surrounding information alters its typography and/or layout to create the needed visual space.

We have demonstrated the value of Fluid Documents in two prototype applications. Fluid Links use animated glosses to support informed and incremental hypertext browsing, and Fluid Spreadsheets use animated graphics to make formulas and cell dependencies visible in a spreadsheet. We have also developed a “negotiation architecture” to support Fluid Document applications. This architecture allows the primary and supporting information to adjust their typography and layout appropriately.

Results of a recent observational study of subjects using Fluid Links indicate that the basic concepts underlying fluid documents can be effective: users can process moving text even in a serious reading situation, and providing information close to the anchor seems to be beneficial. Subjective preferences were varied, which suggests that architectures like our negotiation architecture, which supports multiple fluid techniques, may be crucial to user acceptance.

More on the project web site.

D. D. Salvucci. Inferring intent in eye-based interfaces: Tracing eye movements with process models. In Proceedings of the SIGCHI conference on Human factors in computing systems, pages 254–261, Pittsburgh, Pennsylvania, USA, May 15-20 1999. Association for Computing Machinery. [pdf]

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While current eye-based interfaces offer enormous potential for efficient human-computer interaction, they also manifest the difficulty of inferring intent from user eye movements.  This paper describes how fixation tracing facilitates the interpretation of eye movements and improves the flexibility and usability of eye-based interfaces.  Fixation tracing uses hidden Markov models to map user actions to the sequential predictions of a cognitive process model.  In a study of eye typing, results show that fixation tracing generates significantly more accurate interpretations than simpler methods and allows for more flexibility in designing usable interfaces.  Implications for future research in eye-based interfaces and multimodal interfaces are discussed.

The main argument of this paper is that fixation tracing facilitates the analysis of eye movements to the user intentions that produced them. Tracing is the process of inferring intent by mapping observed actions to the sequential predictions of a process model. Fixation tracing interprets protocols by means of hidden Markov models, probabilistic models that have been used estensively in handwriting recognition.

Fixation tracing, according to the author, can interpret eye-movement protocols as accurately as human experts and can help in the creation, evaluation and refinement of cognitive models.

The author concludes saying that greater potential arises in the integration of eye movements with other input modelities as for instance, an interface in shich eye movements provide pointer or cursor positioning while speech allows typing or directed commands.

Tags: eye-tracking, human communication, human computer interaction

R. E. Kraut, S. R. Fussell, and J. Siegel. Visual information as a conversational resource in collaborative physical tasks. Human-Computer Interaction, 18:13–49, 2003. [pdf]

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Visual information plays two interrelated roles in collaborative work: first it helps people maintin up-to-date mental models or situational awareness (Endsley, 1995) of the state of the task and others’ activities; second it helps people communicate about the task, by aiding conversational grounding (Clark, 1981). The authors’ assumption is that the usefulness of a video system for remote collaborative work depends on the extent to which the video configuration makes the same visual cues available to collaborators that they use when performing the task when co-located.

Communication media limits the visual information that can be shared, with resulting effects in the collaboration process and performance. To test the hypotheses raised by this intuition, the uathors conducted two experiments using a bike-repair task whern an expert was guiding a novice repairing a bike with various communication settings. The authors varied the presence of a visual channel and used a control condition given by face-to-face interaction.

Psysical tasks can be performed most efficiently when a helper is physically co-present. Having a remote helper leads to better performance than working alone, but having a remote helper is not as effective as having a helper working by one’s side. The visual information was valuable for keeping haware of the changing state of the task.

Communication was more efficient in the side-by-side condition, where the helper spent more time telling the worker what to do. In the mediated condition, not only the dialogues longer, but their focus shifted: more speaking turns are devoted to acknowledging the partners’ messages.

One of the limits of this study is that they used an head-mounted video camera to show to the worker the focus of attention of the helper. This might not give the right information as the worker’s camera view might still contain too much information to be effectively used.

The authors conclude with four implications for design that I report below:

(1) Provide people with a wide field of view, including both task objects and the wider environment, so that they can more easily maintain task awareness and ground conversations;

(2) Clarify what is part of the shared visual space. All parties to the task should have a clear understanding of what one another can see; that is, the contents of the shared visual space should be part of participants’ mutual knowledge or common ground;

(3) Provide mechanisms to allow people to track one another’s focus of attention. When people can see where each person is looking, it is easier to establish common ground;

(4) Provide support for gesture within the shared visual space. Talking about things is most efficient when people can use a combination of deictic expressions and gestures to refer to task objects.

Tags: Computer Supported Collaborative Work, eye-tracking, research