SCRIPTS IN A FRAME: A FRAMEWORK FOR ARCHIVING DEFERRED REPRESENTATIONS

Justin Brunelle, PhD Candidate, Old Dominion, University

This dissertation explores the following: why JavaScript and deferred
representations are difficult to archive (establishing the term deferred
representation to describe JavaScript dependent representations); the extent to
which JavaScript impacts archivability along with its impact on current
archival tools; an automated method to measure the quality of mementos, which
we use to describe the impact of JavaScript on archival quality; the
performance trade-offs between traditional archival tools and technologies that
better archive JavaScript; and a framework for discovering currently
unarchivable descendants (representations generated by client-side user events)
to mitigate the impact of JavaScript on our archives.

We propose a two-tiered crawling approach that enables crawlers to capture
embedded resources dependent upon JavaScript. Measuring the performance
benefits between crawl approaches, we propose a classification method that
mitigates the performance impacts of the crawling approach, and measure the
frontier size improvements observed with the two-tiered approach. Using the
two-tiered approach, we measure the number of client-side states associated
with each URI-R and propose a mechanism for replaying these joiner mementos of
deferred representations.

In summary, what we archive is increasingly different from what we as
interactive users experience. Using the approaches detailed in this
dissertation, archives can create mementos closer to what users experience
rather than archiving the crawlers’ experiences on the Web.