Why can't I find this thesis or dissertation?

The work may not have been digitized: 

• Dissertations at Harvard weren't digitized as a rule until 2012, when our online repository (DASH) was created. Most pre-2012 works can be found in print only.
• The situation is similar at many institutions; to date, the majority of these works have never been digitized.
• At one time, a few companies sold microfilm packages of some theses & dissertations (which you'll find in the library catalog where available).

The copyright may be protected: 

• Many institutions are protective of their student authors' copyright. They won't scan more than a few pages without the author's permission and may have restrictive policies; it may take time to reach the author for approval of a digitization request. 
• ProQuest sometimes will need to acquire an author's permission. If it's listed in ProQuest as full text unavailable, you can call ProQuest at 1-800-521-3042 to see if you can get a copy from them with the author's permission. It will be up to you to locate the author.

The material may be under embargo: 

• Many newly minted grads hope to publish this work in some format or other, so it may be listed in the library catalog or institutional repository but with a notice of embargo. This means the work will not be freely available until a predetermined time (usually within 5 years or so). 

The work may not have been collected: 

• At Harvard, the library collects only Honors undergraduate theses and these are listed in our catalog, HOLLIS. 
• All undergrads are encouraged to submit their theses to DASH (our institutional repository) but it isn't a requirement, so we have fewer digitized undergraduate theses. 

Suggestions:

• The author may have published the work in another format that could work for you. 
• Often the library of the degree-granting institution is the only place where a print copy exists unless the author kept a copy (which varies widely.) 
• For more recent work, sometimes the best option is simply to ask the author (through public contact info at their current institution or via social media like LinkedIn).
• If you can't even find a listing for the work:
  • Try the library of the degree-granting institution to see if they have any record of it.
• For more ideas, see "How can I find a thesis or dissertation?" 

For Harvard dissertations, see "How can I find a Harvard thesis or dissertation?"
For Harvard undergrad theses, see "How can I find an undergraduate thesis?"