The University of Michigan has been studying which of the digitized books it holds are orphans. That project is described here, including the workflow process:
Note that two different people follow the same workflow for each volume, which is a built-in protection against making errors. We attempt to make contact with the potential copyright holder via two (and sometimes three) different ways. If we make contact with a potential rights holder and they assert that they are still in fact the rights holder for the work, it is not an orphan. If we can not make contact with a potential rights holder or the potential rights holder does not assert that she holds the rights, then only at that time do we consider the work an orphan.
Of special note is the fact that a list of potential orphans will be made available for 90 days before they are opened. If, at any time, a legitimate copyright holder approaches us we will remove their work from our pool of potential orphans (as it is no longer an orphan). In addition, if at any time after a work has been identified as an orphan and made readable to the U-M scholarly community a legitimate copyright holder approaches us, we will remove the copyright holder’s work from the program.
Now, for those books that have passed through this process and been categorized as “orphan,” the University library will make them available to University users and campus visitors:
Access to orphan works will be limited to U-M authenticated users and visitors to the campus libraries in Ann Arbor, and to works that the library holds in its print collection. In other words, the same population that can check out these works from the library’s print collection now will be able to read the digital copies from other locations.
According to John Wilkin, associate university librarian and executive director of HathiTrust, other institutions among the HathiTrust’s more than 50 partners, including the University of Wisconsin, are moving forward with similar plans to share digitized orphan works from their own collections.