The collaborative possibilities afforded by tabletop interfaces make them appealing for sharing digital files and
personal information between group members. Although users may not perceive a tabletop interface as a
conventional personal computer, a form of file system interface seems important: A file system,
and its interface, constitute a core facility of an operating system. In this project, we are exploring
tabletop file system access, taking particular care with those aspects that distinguish tabletop interaction,
notably their role for collaborative interaction. The following is an example scenario that illustrates requirements on tabletop
file access:
James and Alice have an assignment to design a Greek history museum exhibit. James is discussing the project
requirements with the exhibition co-ordinator via e-mail, and collecting photographs of Greek artefacts. Alice is
doing research to write descriptions of these artefacts, and associated aspects of ancient Greece. James and
Alice now need to combine their work, making decisions about which artefacts to use in the exhibition. They
choose the tabletop to support this collaborative activity.
Tabletop interfaces are appealing for tasks like this, involving sharing of digital files and personal
information. Notably, this scenario involves multiple file systems because James would naturally have used his
own computer for work, while Alice would have used hers. Now, they need their files to be available at the
tabletop. Although the e-mail, images and text may happen to be in arbitrary hierarchies on those computers, we
want to facilitate easy and natural access to all the relevant files and to exploit each user's own knowledge of
their own file system, while supporting collaboration with the combined file-set at the tabletop.
Hierarchical organisation and navigation of file systems has become the standard in conventional personal
computers. However, the properties and constraints of multi-user tabletop interaction call for rethinking
this standard approach to file system interaction. First, there are limitations of physical interaction that
affect how information can be presented, and how user input can be accepted. These limitations are the result of
a low resolution on the tabletop, which is needed to make targets sufficiently large for direct-touch
interaction. A keyboard and mouse is typically not present in a multi-user tabletop setting. Even a projected
keyboard on the tabletop surface is problematical---there is no tactile feedback on pressing keys, and it lacks a
fixed reference for users to place their hands (a serious problem when the projected keys would be occluded by a
user's hand). Collaborative tabletop interfaces must also be orientation independent (as people could be sitting
anywhere around the table). This poses problems for text presentation, such as file and directory names.
Finally, the collaborative nature of the tabletop interface encourages users to share their files with each
other, meaning that the files presented on a tabletop often need to come from multiple collections. Required
documents may be in various folders across the separate file systems, and retrieving a particular document may
only be possible for the user who owns that file system. While users may have a hierarchical mental model of file
system interaction, we need to explore alternative approaches, as a core requirement of a tabletop file system
interface is the ability to interact with multiple (and potentially unfamiliar) large collections of files.
In this project, we have built from the Cruiser platform to develop a novel way of
interacting with a file system, designed specifically for collaborative tabletop exploration of multiple file systems.
File navigation is based on the notion of a focus file. Once a user selects a focus file, all other related
files are displayed (regardless of where they are stored or which file system they belong to). A user may navigate the file systems
by re-selecting focus files. The focus file approach allows content-based file access without any user text entry. To select a focus
file, a user dwells (depresses the pen for one second) on an image representation of the document. A `click' sound gives
feedback that it has been selected. After each focus selection the initial size of a file is used to indicate its relevance
to the focus, and irrelevant files are automatically hidden in order to reduce clutter on the tabletop. The screenshot on the right
shows a collection of documents after two successive focus selections from the initial start view.
Key Publications
A. Collins and J. Kay. Collaborative personal information management with shared, interactive tabletops. In Proceedings of Personal Information Management 2008 (a CHI 2008 Workshop), 2008. [View Details]
A. Collins. Tabletop file system and personal information management in pervasive computing. In Advances in Pervasive Computing: Adjunct Proceedings of the 6th International Conference on Pervasive Computing, pages 160-166. Österreichische Computer Gesellschaft, 2008. [View Details]
A. Collins. Enabling collaborative tabletop file system interaction through similarity-based browsing. 2008. Grand finalist paper submission for the ACM Student Research Competition 2007. [View Details]
A. Collins. Exploring tabletop file system interaction. In CHI '07: CHI '07 Extended Abstracts on Human Factors in Computing Systems, pages 2171-2176, New York, NY, USA, 2007. ACM Press. [View Details]
A. Collins, T. Apted, and J. Kay. Tabletop file system access: Associative and hierarchical approaches. In TABLETOP '07: Proceedings of the Second Annual IEEE International Workshop on Horizontal Interactive Human-Computer Systems, pages 113-120, Washington, DC, USA, 2007. IEEE Computer Society. [View Details]
A. Collins and J. Kay. Systems and methods for file transfer to a pervasive computing system. Australian Provisional Patent 2007231829, Smart Internet Technology CRC Pty Ltd, Sydney, NSW, Australia, 2007. [View Details]
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