Sunday, April 10, 2011

Review of CHI 2006 Article on Tabletop Displays

This semester I am taking a User Interface Design course (CIS577). As part of the course work, we have been required to review articles that have been published. The below review is from an article published in 2006.
Ref: Tang, et al. Collaborative Coupling over Tabletop Displays. In Proc. CHI '06, ACM Press (2006), 1181-1190.


Review of Collaborative Coupling over Tabletop Displays

Collaborative Coupling over Tabletop Displays is an article written by five researchers (Tang et al.) from the Universities of British Columbia and Calgary. The article focuses on this group’s research of designs for collaborative interfaces for tabletops and presents their methodologies and observations of two different studies. Additionally, the implications of implementing at least one method, as well as the group’s overall conclusions are presented.
Tang et al. initially presented the confusion that is generally inherent in the study of collaborative efforts. The referenced efforts of study focused on group activities using both traditional (non-interactive) and interactive desktops. During this explanation of some of the difficulties in studying collaboration some important key words and phrases were defined:
- mixed-focus collaboration – the frequent bi-directional transition between individual and shared tasks
- coupling – as used in this article, coupling refers to: collaborative coupling style
- three viewing technologies
o lenses – show information in spatially localized areas
o filters – show information globally
o Shadowboxes – allows spatially localized areas to be displaced
Before delving into the details of Study 1, the authors present some additionally important information in the three primary sections of: Collaborative Coupling, Background, and Overview of Observational Studies.
In their discussion of Collaborative Coupling, the authors reiterate the important point that: the efforts of a group cannot be easily divided into only the two categories of “independent” or “shared.” They further explain that collaborative coupling refers to “manner in which collaborators are involved and occupied with each other’s work.” Coupling, as used by the authors, refers to both a level of workspace awareness and of a “desire to work closely or independently of one another.”
The Background and Overview sections provide a full discussion of the issues facing current research involving the design of collaborative tabletops. In these sections additionally important terms such as coordination, interference, and territories are defined and discussed. While all three of these terms are relevant to this study, the definition and use of interference seems to play more direct role in the studies and results. Interference is used by the authors to describe any user, system, or environmental action or attempted action. For example, interference can be when two individuals attempt to manipulate the same object. Likewise, interference can be the execution of a command that re-positions multiple objects, thus introducing the need for users to re-learn the location of each object prior to their use.
The discussion of Study 1 indicates that study 1 was focused more on the learning/identification of how groups and individuals coordinate themselves when presented with a “spatially fixed visualization.” The authors indicated that more than one of their hypotheses had been disproven. Specifically of note was the disproving of their expectation that individual members of the group would naturally favor individual efforts as opposed to group collaboration. Empirically, the authors identified that participant efforts were visibility independent for only 24% of the total time. This revelation appears to be the actual driving factor behind the authors conducting a second study; the authors were unclear as to if Study 2 would have been deemed necessary had more of their hypotheses been proven.
During Study 1, it was noted that the individuals not only preferred to work together, but that they also preferred the “group-type” visualization tools (global filters). The task that each group was assigned was that of developing a route (using specific constraints) of travel through a fictitious city as displayed on a tabletop. The individuals tended to move and work together naturally, which was contrary to the authors’ hypothesis.
Study 2 was conducted under established conditions that were based upon the outcomes of Study 1: explicit individual tasks and roles, a redesigned lens widget, conflicting data layers, the removal of the ShadowBox, and the implementing of multiple sub-problems. The other differences between Studies 1 and 2 are: a slightly different set of test subjects and a custom man-made graph (fully connected) was used in Study 2 as opposed to the fictitious city map of Study 1. Whereas Study 1 revealed coordination of groups over spatially fixed visualizations, Study 2 revealed that there were six distinct styles of coupling: (SPSA) – Same Problem Same Area, (VE) – View Engaged, (SPDA) – Same Problem Different Area, (V) – View, (D) – Disengaged, and (DP) – Different Problems.
Study 2 appears to be a logical extension of Study 1, and in fact could be relabeled as Study 1 Part 2. The introduction of more guidance and stipulations in Study 2 did allow for the validation of the results from Study 1 as well as Study 2’s own results and observations. In conducting these studies and reviewing the results, the authors drew some relatively helpful conclusions regarding the methodology used in tabletop interface design.
However, it is evident that if this research is accepted as the sole authority, then there is no clear single approach that can be utilized for the design methodologies of interactive tabletops. The authors state that a “flexible set of tools allowing fluid transitions between views is required to fully support the dynamics of mixed-focus collaboration”.