Quick answer: To find past dissertations in your field, search ProQuest Dissertations and Theses Global through your library for the broadest US coverage, then check open aggregators such as OATD and the NDLTD portal, state or consortium repositories such as the OhioLINK ETD Center, and the repositories of the universities that publish the most work in your topic. Use them to see how committees structure a study like yours, to find antecedent studies for your literature review, and to cite correctly, never to copy.

This guide compares the main sources, gives a search-by-topic workflow, and shows how to cite a dissertation in APA style. For a long directory of open repositories worldwide, see the directory of open-access thesis repositories, which also covers repositories outside the United States; this article is narrower: US students looking for dissertations on a topic.

Why look at past dissertations at all?

Past dissertations answer questions that journal articles do not. How long is a typical chapter three in your program? How did previous students define their population, justify a sample size or present limitations? Which instruments did they use, and what reliability did they report? Which gaps did they list for future research? Reading three or four recent dissertations from your own department is often the fastest way to calibrate what your committee will accept. They are also a source of antecedent studies: the reference lists of a good dissertation on your topic are a ready bibliography, and dissertations often report null or small-sample results that journals do not publish.

The sources compared

No single source is complete. A recent dissertation may be embargoed, may appear only in the university repository, or may reach ProQuest months after the defense. Plan to search at least two of them.

A search-by-topic workflow that works

1. Write your topic as three or four concept words. For example “teacher retention”, “rural”, “mixed methods”. Add synonyms for each concept.
2. Search ProQuest first through your library. Limit document type to dissertations and theses, restrict the date to the last five to eight years, and combine concepts with AND and synonyms with OR. The guide to Boolean search strings explains how the same string behaves differently between databases.
3. Repeat the search in OATD. Use the same concept words and compare results; a record that shows up in both is likely to be freely available.
4. Search your own university’s repository by department. Browse recent completed work in your program and filter by degree type, because a doctoral dissertation, a master’s thesis and a capstone project differ in length and structure.
5. Chase the reference lists. Take the best two or three dissertations and read their literature reviews and reference lists to find the studies everyone in your topic cites.
6. Record every search. Note the source, date, string and the number of hits, so you can describe your search in the methods or literature review chapter.

If you need more search practice, the guide to the best academic search engines compares tools for finding journal literature alongside these thesis sources.

A worked search, step by step

The example is illustrative. Suppose your topic is why teachers leave rural schools. Your concept words are teacher retention, rural and school. Synonyms for the first might be teacher attrition, teacher turnover and teacher mobility. A first string for ProQuest could combine them as (teacher retention OR teacher attrition OR teacher turnover) AND rural AND school, limited to dissertations from the last seven years. If the result list is huge, add a fourth concept such as a state, a method or a population. If it is tiny, drop the least important concept or widen the date range. Skim titles and abstracts, shortlist about ten, and open the full text of the three closest to your design. Then run the same concept words in OATD and your own repository and add any new records to the shortlist.

Match the degree type before you compare

A master’s thesis, a professional doctorate capstone and a research doctorate dissertation are different sizes with different expectations. A master’s thesis may have a short literature review and a small sample, while a doctoral dissertation is expected to make a larger original contribution. Compare like with like: if your program writes a three-chapter capstone, do not model your chapter lengths on a six-chapter dissertation from another university. Look at the front matter of each candidate to confirm the degree and the department before you invest time reading it.

What to look for when you open a dissertation

• The abstract and table of contents, to confirm the design and the chapter structure match yours.
• Chapter three, for the sampling procedure, instruments, reliability, ethics approval and analysis plan.
• The limitations and recommendations, where earlier authors list the gaps your study might address.
• The appendices, where you may find consent forms, interview guides and permission letters.
• The committee and the date, since expectations and methods change over time.

Prefer dissertations from the last few years and from programs similar to yours. A ten-year-old dissertation may cite outdated standards or old versions of instruments.

Using a dissertation’s literature review to build yours

A strong dissertation’s literature review is a map. Read its headings to see how the author grouped the field, then read the cited sources yourself rather than relying on the author’s summary. A dissertation can be wrong, incomplete or out of date, and a summary of a summary drifts from the original. Treat the reference list as a set of leads, and cite the original article where you can. Where you must cite the dissertation itself, because it contains a finding or an instrument you cannot find elsewhere, say clearly that the evidence comes from an unpublished or non-peer-reviewed source.

How to use them without plagiarizing

Treat a dissertation as a source, not a template to copy. Cite it whenever you use its ideas, findings or wording, paraphrase in your own words, and keep quotations short. Using someone else’s chapter structure is acceptable and normal, but reusing their sentences, tables or figures without citation is not, and a similarity report may flag text from repositories. Never use a dissertation’s instrument items or figures without checking permission terms. If you adapt a research design, say so in your methods chapter and cite the source. The guide to text recycling rules covers the related issue of reusing your own earlier work.

How to cite a dissertation in APA style

APA 7th edition treats a dissertation or thesis as a standalone work, with the degree type and the institution in square brackets after the title, and the source database or repository named at the end. The patterns below follow that format; check the APA Style website for the current examples before you finalize your reference list.

• From a database such as ProQuest: Author, A. A. (Year). Title of dissertation [Doctoral dissertation, Name of University]. ProQuest Dissertations and Theses Global.
• From a university repository: Author, A. A. (Year). Title of dissertation [Doctoral dissertation, Name of University]. Name of Repository. URL
• Unpublished and not available online: Author, A. A. (Year). Title of dissertation [Unpublished doctoral dissertation]. Name of University.

Replace “Doctoral dissertation” with “Master’s thesis” where appropriate. In the text, cite it like any other source with the author and year. If you found the same work in two places, cite the version you actually read, and prefer the stable repository link where one exists.

Embargoes, access problems and what to do

Many universities allow authors to delay public release for months or years to protect publications or patents, so a dissertation you want may be listed but not downloadable. Your options are to check whether the same work is in ProQuest, to ask your library for interlibrary loan, to contact the author through the repository record, or to use the published articles that came from it. The guide to whether you have to publish your thesis explains why embargoes exist, which helps when you plan your own deposit.

Common mistakes

• Searching only Google and missing dissertations that live in repositories or ProQuest.
• Copying a dissertation’s structure and phrasing too closely and being flagged by a similarity report.
• Relying on a single old dissertation instead of several recent ones.
• Citing a dissertation without the degree type, institution or source.
• Using an instrument from a dissertation appendix without permission.
• Skipping your own program’s repository, where the closest examples often sit.

Where Tesify fits

Once you have found your comparison dissertations, Tesify’s thesis workspace helps you structure your own literature review and methods chapters around what you learned; 9,000+ students have written 15,000+ chapters with Tesify. Every word stays 100% written by you, and Tesify cannot search a library database for you or confirm that a source says what you cite.

Frequently asked questions

Is ProQuest Dissertations and Theses Global free?

It is usually available through a university library subscription rather than free; check whether your library provides it and whether alumni access exists.

Is OATD free to use?

The portal is free to search; whether you can read the full text depends on each institution’s repository and any embargo.

Can I use a dissertation as a source in my literature review?

Yes, if you cite it, but prefer peer-reviewed articles for central claims and use dissertations for context, methods and additional evidence.

How do I cite a dissertation I found in a repository?

Use the APA pattern with the degree type and institution in brackets, then the repository name and URL, and check the APA Style website for current examples.

How recent should the dissertations I use be?

Aim for the last five to eight years where you can, because standards, instruments and statistical practice change.

Can I copy a dissertation’s methods section?

No. You can follow a similar design and structure, but write your own text and cite the source of the design.

What if the dissertation is embargoed?

Try ProQuest, interlibrary loan or the author, or use the journal articles published from the work.

Should I search my own university’s repository?

Yes. The dissertations of your own department show the format and expectations your committee actually applies.