  Computers are used for various purposes, so frequent context switching is
inevitable. In this setting, retrieving the documents, files, and web pages
that have been used for a task can be a challenge. While modern applications
provide a history of recent documents for users to resume work, this is not
sufficient to retrieve all the digital resources relevant to a given primary
document. The histories currently available do not take into account the
complex dependencies among resources across applications. To address this
problem, we tested the idea of using a visual history of a computer screen to
retrieve digital resources within a few days of their use through the
development of ScreenTrack. ScreenTrack is software that captures screenshots
of a computer at regular intervals. It then generates a time-lapse video from
the captured screenshots and lets users retrieve a recently opened document or
web page from a screenshot after recognizing the resource by its appearance. A
controlled user study found that participants were able to retrieve requested
information more quickly with ScreenTrack than under the baseline condition
with existing tools. A follow-up study showed that the participants used
ScreenTrack to retrieve previously used resources and to recover the context
for task resumption.
