Performance and interaction behaviour during visual search on large, high-resolution displays.

Large, high-resolution displays (LHRDs) allow orders of magnitude more data to be visualized at a time than ordinary computer displays. Previous research is inconclusive about the circumstances under which LHRDs are beneficial and lacks behavioural data to explain inconsistencies in the findings. We conducted an experiment in which participants searched maps for densely or sparsely distributed targets, using 2 million pixel (0.4m × 0.3m), 12 million pixel (1.3m × 0.7m) and 54 million pixel displays (3.0m × 1.3m). Display resolution did not affect the speed at which dense targets were found, but participants found sparse targets in easily identifiable regions of interest 30% faster with the 54-million pixel display than with the other displays. This was because of the speed advantage conferred by physical navigation and the fact that the whole dataset fitted onto the 54-million pixel display. Contrary to expectations, participants found targets at a similar speed and interacted in a similar manner (mostly short panning movements) with the 2- and 12-million pixel displays even though the latter provided more opportunity for physical navigation, though this may have been because panning used velocity-based control. We are applying these findings to the design of a virtual microscope for the diagnosis of diseases such as cancer.