Several tools for discovering journal articles, such as Web of Science, IEEE Xplore, PubMed, and ScienceDirect, now have ways for you to limit a search to open access articles or to identify the open access articles within the result set of your search. Open access articles are free to read regardless of the reader’s access to the published articles via institutional subscriptions.
Due to the importance of being able to identify open access articles and to know what kinds of uses of these are permitted, NISO is sponsoring a working group of stakeholders to develop “Recommended Practices for Open Access Metadata and Indicators“. The adoption of standard metadata will enable transfer of that data among information providers and publishers, and further enhance discovery of this information, including in web scale discovery services like Summon.
Meanwhile, you can use the following tools to locate open access articles; look for similar options in other search tools:
In the new Web of Science platform, run your search, display results, and find the open access option at the end of the “Refine Results” list of options. This will show you the number of articles in your result that are OA; then apply “refine” to limit your set to these.
IEEE XPlore offers the option at the search page:
PubMed offers a filter for “free full text”.
ScienceDirect provides browsing of journals by “open access” for completely open journals or “contains open access” for those where some article are open access, as well as a refinement on your search to open access articles.