This paper presents the results of an experiment that considered whether a haptic force feedback interaction improves virtual presence, perceived social presence, perceived task performance, and task performance in shared tasks carried out in a desktop virtual environment.

The paper clearly describes the experiment, and as such proves a useful model for describing and reporting experimental results in general.

The authors claim that the results demonstrate that “haptic force feedback gives added support to people performing collaborative tasks in a multimodal interface.” Three of the five tasks in the experiment, however, can be carried out without the virtual assistance of one of the participant pairs. The experiment does not seem to control for the degree to which any pair worked together or separately for these tasks.

While it is clear from the results that haptic force feedback did improve most measures for this experiment--an important result--it is not clear to what degree this improvement is in shared or unshared task experience, so the authors’ claim may or may not be justified.

It would be worth repeating the experiment, using a design that requires collaboration for each task.