Gutwin, C. and Greenberg, S. (1999b). The Effects of Workspace Awareness Support on the Usability of Real-Time Distributed Groupware. ACM Transactions on Computer-Human Interaction (TOCHI) 6 (3), 243-281. Gutwin and Greenberg (1999b) compared peoples performance in two groups of pairs. The first group of participants used simple groupware system and the other used an awareness-enhanced system. In both systems, the medium-sized visual workspace allow people to collaborate by creating, manipulating and organizing artefacts. The participants were given a pipeline construction kit. Each pair had to assembly and manipulate simple pipeline in a shared two-dimensional workspace. In the first condition, participants did not have any awareness tool. In the second condition, a radar view added on the main view into the top left corner showed the entire workspace in miniature. This AT showed the viewport of the current user and the partners ; it also shows both mouse cursors. Thus this radar view provided visual indications of the other persons location, the location of his or her cursor, and the motion of objects that he or she moved. Participants had to complete three different tasks : assembly pipe so as to meet another person at a specified location, constructing two identical structures from two existing stockpiles of pipe sections and finally verbally guiding the other partner in order to add specific sections to an existing network. The authors examined five variables : completion time, verbal efficiency (number of words spoken, classified in categories), perception of effort (questionnaire), overall preference (questionnaire) and strategy use. The authors noticed the following results : the group with AT completed the task more quickly (for task 1 and 3) and more efficiently (with less words spoken). Beside, adding AT to a groupware system seemed to improve peoples satisfaction. They interpret the fact that the use of an AT increase the performance by claiming that the radar view allowed visual communication. For instance, workspace locations were easier to describe in the AT conditions since the user could see exactly where his partners view and telepointer were ; they could also provide relative directions based on the partners current location. Gutwin and Greenberg also claimed that the AT, by providing continuous feedback (about piece location for example) and feedthrough enables the player to increase their performance. Moreover, the awareness information enabled participants to use different and more effective strategies to perform the tasks. They recorded the strategy used by partners to indicated locations and to indicates pipelines sections. They also identified different strategies subjectively by watching the session videotapes. Participants used a wide range of methods, both verbal and non-verbal for indicating locations and pieces. For instance some gave directions base on the other persons current location (e.g., up and left from where you are), a description of an object at the location or directions based on a previously identified location. Gutwin and Greenberg noticed differences in strategy use between the two conditions that can be partly attributed to the information available in the two interfaces (simple system and awareness-enhanced system). It seems that pairs in the condition without AT used a wider range of strategies than pairs with AT. Furthermore, the two different groups did not use the same strategy. Strategies used for directing and indicating:
| Strategy | Description |
| Relative-to-you | Directions base on the other persons current location : e.g., up and left from where you are |
| Describe-location | A description of an object at the location: e.g., the squiggly-looking thing |
| Left-right-top-bottom | Rough coordinates system dividing the workspace into four blocks: e.g., next one is in the top left corner. |
| Relative-to-previous | Directions based on a previously identified location: e.g., near where we were for the last one. |
| Map-coordinates3x3 | Directions based on a 3-by-3 grid: e.g., go to 1,2 |
| Pipe-tracing | Directions to follow a line of pipe: e.g., follow this pipe along to the right, and then it goes up |
| Follow-rectangle | One person tracks the other by following his or her view rectangle in the radar |
| Relative-to-us | Directions given when both participants are in the same place: e.g. now down and a little to the left from here |
| Move-piece-to-show | One person moves a pipe section to indicate a location through the radar or the overview |
| 1D-relative-and-wait >/td> | Directions to move up, down, left, or right, after which the person giving directions waits until success is established |
| Follow my cursor | One person follows the others main view cursor |
| Describe-piece | A description of the next piece to be used: e.g., its an elbow section with a medium straight on the end |
| Show-by-move | The piece is moved back and forth in the storehouse |
| Show-by-drag | The piece is dragged up to the construction area |
| Show-by-placing | The piece is moved to the construction area and placed. |