Unpaywall is a third-party service that helps identify materials that may be available somewhere in an open access format. In OneSearch, it is set up so that if an item is only available to us in an open access format, a link to it will be made available in the item record in the “View Online” portion, as can be seen in this sample record:
If you click through to the permalink for this record in OneSearch, though, and then click the link for Unpaywall, you’ll see that the item in question is actually not open access (the accompanying videos are but the text of the conference paper is not). Unpaywall sometimes makes mistakes like this (a false positive) about the OA availability of an item. Please report each one of these false positives you find so that the OLS Discovery Working Group can consider whether this integration of Unpaywall is worth keeping.