Quantifying Orphaned Annotations in Hypothes.is

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. In this paper, we investigate the prevalence of orphaned annotations, where a live Web page no longer contains the text that had previously been annotated in the Hypothes.is annotation system (containing 6281 highlighted text annotations). We found that about 27% of highlighted text annotations can no longer be attached to their live Web pages. Unfortunately, only about 3.5% of these orphaned annotations can be reattached using the holdings of current public web archives. For those annotations that are still attached, 61% are in danger of becoming orphans if the live Web page changes. This points to the need for archiving the target of annotations at the time the annotation is created.