  Web annotation has been receiving increased attention recently with the
organization of the Open Annotation Collaboration and new tools for open
annotation, such as Hypothes.is. We investigate the prevalence of orphaned
annotations, where neither the live Web page nor an archived copy of the Web
page contains the text that had previously been annotated in the Hypothes.is
annotation system (containing 20,953 highlighted text annotations). We found
that about 22% of highlighted text annotations can no longer be attached to
their live Web pages. Unfortunately, only about 12% of these annotations can be
reattached using the holdings of current public web archives, leaving the
remaining 88% of these annotations orphaned. For those annotations that are
still attached, 53% are in danger of becoming orphans if the live Web page
changes. This points to the need for archiving the target of an annotation at
the time the annotation is created.
