Reference audit of 93 theses approved in 2026
We audited 93 theses (those whose reference lists could be read, out of 100 drawn at random from the theses approved in 2026 by the Turkish Council of Higher Education (YÖK) National Thesis Centre). Every one of the 14,888 references in these theses, from 59 different universities, was checked one by one against open scholarly databases.
Key findings
- Of the 14,888 references in 93 theses approved in Turkey in 2026, 68% were verified in open scholarly databases.
- 41 of the 93 theses contained at least one reference with a broken DOI: 113 DOIs resolved to nothing, and 67 pointed to a completely different publication.
- 374 of the 14,888 references (2.5%) were flagged as suspicious by the automated check, a flag that requires manual confirmation.
- Suspicious references are concentrated in a few theses: 27 theses have none, 43 have between 1 and 5, and a single thesis accounts for 45.
- Most unverified references are not errors: the largest group is sources not expected in open indexes, such as older and Turkish books, newspaper articles and archival documents.
Each column groups theses by how many suspicious references they contain; the grey column is theses with none.
How it was done
The sample was drawn by thesis number
Theses were selected at random by their national thesis number rather than by archive or university, so no institution, field or repository is over-represented. The random seed (20260920) is on record: a third party can reproduce the same 100 theses. The reference lists of 93 of them could be read; in 7 the reference section could not be extracted reliably or no full text was available, and these are excluded from the figures.
Full texts came from open access
All full texts were downloaded from the YÖK National Thesis Centre, from copies the authors had released for open access; the reference section was extracted and each entry queried separately.
The audit is deterministic
No generative AI was involved in the verification verdict: each entry was compared with the records of 19 international databases and catalogues, and every DOI was resolved.
Update: 26 October 2026
In the first version of this study (22 September 2026), PDF page numbers that ran into the DOI of an entry made some genuine references appear to have unresolvable DOIs. After this reading error was fixed, the same theses were audited again from scratch; every figure on this page is from the new run. The first version reported 13,961 references from 100 theses. The corrected reader extracts reference lists more completely, so the count per thesis rose, while 7 theses whose reference section could not be read reliably were excluded (93 theses, 14,888 references). The first version remains archived on Zenodo and may still appear under its original title in some indexes.
The report is anonymous
No thesis, author or supervisor name was recorded at any point. The published dataset contains only thesis type, year and counts; none of the universities is named individually.
What “not verified” means
Not all of the 4,760 unverified or suspicious references are faulty. The largest group is sources not expected to appear in open indexes at all (older and Turkish books, newspaper articles, archival documents), followed by records found in no index and genuine metadata errors.
| Reason | References |
|---|---|
| Out of scope (books, newspapers and archival sources, theses, web pages) | 1,763 |
| Not found in any index | 1,627 |
| Metadata error (author, year, title, volume/issue) | 917 |
| Match inconclusive | 270 |
| DOI problem (unresolvable or mismatched) | 183 |
Which database confirmed the reference?
No single index was relied upon; national catalogues were queried for Turkish-language sources.
| Database | Verified |
|---|---|
| 19 international databases and catalogues | 10,023 |
| Web pages (title confirmed) | 105 |
Limitations
- “Suspicious” is an automated verdict and requires manual confirmation; on its own it is not proof of fabrication. A DOI may fail to resolve simply because the publisher registered it late.
- Verification rates fall in the humanities: Turkish books, Ottoman-era works, newspapers and archival documents are absent from open databases and therefore count as “not verified”. This is a limit of coverage, not of the thesis.
- The sample covers only theses released for open access; embargoed theses are outside it.
- The study measures a single year (2026) and contains no comparison with earlier years, so it cannot support claims about an increase or decrease.
Cite this study
The study is archived on Zenodo with a permanent identifier (DOI); please cite it as below.
Özdemir, C., & Gedik, M. A. (2026). Reference integrity in 2026 graduate theses: an automated check of 14,888 references from 93 theses (YÖK National Thesis Center). Zenodo. https://doi.org/10.5281/zenodo.22994564
Data and reproducibility
Per-thesis results are published as an anonymous dataset: each row carries thesis type, year, reference count, verified/unverified/suspicious counts and a breakdown of problems. No university or thesis title is included.
Audit your own reference list
The same check runs in seconds on your own bibliography: every reference is searched in open databases, and unresolvable DOIs and metadata errors are flagged.