Velichkovsky, B. M. Communicating attention: Gaze position transfer in cooperative problem solving. Pragmatics and Cognition 3, 2 (1995), 199–222.
Velichkovsky highlighted the importance of transferring gaze information at distance for collaborative work. Two participants were asked to solve a puzzle collaboratively. One of them had access to the solution while the other was operating the moves on the target puzzle. While the participants shared the same visual workspace, one of them had access to the solution but s/he could not rearrange the pieces. Velichkovsky manipulated the participants communication features. In the control condition the participants could only communicate via voice, while in a second condition the gaze of the participant who had access to the solution was projected on the workspace of the other, while in a final condition the one who had access to the solution could use a mouse pointer to show to the other the relevant parts. Both the experimental conditions, transfer of gaze position and pointing with the mouse, improved performance, however he did not register a significant differenb between mouse+voice and the gaze+voice conditon.
He also processed the data on verbal communication to verify changes in the conversation content. He found a significant reduction of the number of words in conditions of direct reference compared to the voice only condition. Spatial words were replaced by deictic demonstratives and definite referring expressions.
His experiment however did not show differences between the direction of the gaze position transfer (expert to novice vs. novice to expert). Also the experiment did not show differences in mouse vs. gaze reference. Gaze direction is intimately tied to the focus of attention, or better yet, to the focus of external forms of attention. This is only rarely the case for manual pointing.
The author argues that the duration of fixation alone is not a perfect correlate of its communicative role. The means that in order to elucidate the communicative aspect in eye-movements linguistic heuristic should be at work. He makes the example of long fixations which temporaly conicide with verbal remarks of the deictic type could trigger the attention of the partner.