A work is in the public domain if:
- It is no longer under copyright (e.g. the term has expired, it has not been properly renewed)
- It does not meet the requirements for copyright protection (ideas, procedures, methods, etc.)
- The author elected to put the work into the public domain many works with the Creative Commons license fall into this category)
- It is a work of the United States government (may exclude the work of independent contractors)
Once a work falls into the public domain, it is no longer copyrightable and anyone may use public domain works without the permission of the copyright holder, who is no longer entitled to the exclusive rights of a copyright holder. These works can be excellent choices for use in teaching and research because there are no permissions required for their use.
Ascertaining whether or not a specific work has fallen into the public domain can be difficult. The only general rules of thumb are that works published prior to 1923 and unpublished works created before 1890 are have fallen into the public domain. The Digital Copyright Slider can help determine when something is or may be under copyright, and when it is in the public domain.Works for which you cannot ascertain or contact a copyright holder are called “orphan works” and are not currently available for use. The Google Books settlement is attempting to create a registry, which should allow the public to access orphaned works through the Google Books search platform. Sources for public domain material and research on the public domain:
- Columbia University Copyright Advisory Office Public Domain Resources
- University of California Copyright Education Public Domain Resources
- Duke University Center for the Study of the Public Domain
- University of Maryland University College Center for Intellectual Property Resources on the Public Domain
NOTE: It is important to be aware of the distinction between materials in the public domain and materials that are open access. Items in the public domain are free from copyright restrictions whereas open access content is available online without access restrictions. Open access material may still be (and probably is) under copyright. The Library maintains a list of Open Access resources that may be useful for linking from your course materials.