They were then asked whether a ``point and click'' mechanism would be appropriate for summoning the full image. Most people felt that this would be intuitive, though several points were raised:
In summary, users' tolerance of visibly degraded images is dependent on their purposes in viewing the image, the kind of image viewed and the context in which the image is placed, although there are also observable differences in people's underlying tolerance levels.
Despite this, users would seem to appreciate a fast and degraded ``preview'' image in place of a full quality picture on a web-page as long as they knew that they could summon the full picture easily.
These findings suggest that pushing compression to the edge of perceptibility and beyond would be acceptable in writing default policies as long as users could easily amend them. But would they? There is no convenient correlation between tolerance and readiness to customise. Some of the most critical users are impatient with software controls, while others would be happy to adjust them at length.
The findings also suggest that units of time are not an intuitive measure for users. Relative terms such as ``faster'' might be more appropriate to describe speed of delivery than actual timings. Since bandwidth varies during downloading and timings cannot be guaranteed, this strategy is supported by local circumstances.