| ---
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| license: cc-by-nc-nd-4.0
|
| language:
|
| - el
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| - en
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| pretty_name: Psepheda - University of Macedonia Theses & Repository
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| task_categories:
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| - text-generation
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| - fill-mask
|
| tags:
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| - greek
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| - theses
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| - dissertations
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| - academic
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| - institutional-repository
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| - university-of-macedonia
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| - dspace
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| - open-access
|
| size_categories:
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| - 10K<n<100K
|
| ---
|
|
|
| # Psepheda (ΨΗΦΙΔΑ) — University of Macedonia Institutional Repository
|
|
|
| **Dataset Language** <br>
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| Modern Greek (primary), with a minority of English-language academic content and occasional multilingual passages (Slavic/Balkan-studies material includes Cyrillic).
|
|
|
| **Dataset Info** <br>
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| This dataset is a cleaned, full-text snapshot of **ΨΗΦΙΔΑ (Psepheda)**, the institutional repository and digital library of the **University of Macedonia** (Πανεπιστήμιο Μακεδονίας, Thessaloniki, Greece), served from `dspace.lib.uom.gr`. Psepheda is a DSpace repository in which students and staff self-deposit their academic work — overwhelmingly **Master's theses and PhD dissertations**, plus bachelor's projects, musical scores, and a number of historical archival documents (e.g. Hellenic Parliament records and old academic publications).
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|
|
| The dataset contains **14,303 records**. Each row is one repository item: its catalogued bibliographic metadata plus the full text of the deposited PDF, extracted to Markdown. Coverage by issue date spans roughly **1900–2026**, heavily concentrated in **2005–2025** (the period of mandatory electronic self-deposit). The bulk of the corpus comes from the University's postgraduate programmes in economics, business administration, applied informatics, accounting & finance, music science, education, and international/European studies (120 distinct repository collections in total).
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|
|
| **Source & Provenance** <br>
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| - Every record links back to its canonical DSpace landing page (`handle_url`, e.g. `http://dspace.lib.uom.gr/handle/2159/168`) and the source PDF (`pdf_url`).
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| - The `content` field was produced by an LLM/vision-based PDF→Markdown extraction of those PDFs. This extraction is faithful for clean digital-born theses but degrades on hard-to-read pages (old scans, music scores, handwriting); see *Cleaning & Known Quality Notes*.
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|
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| **Metadata Info — Schema** <br>
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| The parquet has one row per repository item and 20 columns:
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|
|
| | Column | Type | Description |
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| |---|---|---|
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| | `title` | string | Title of the document as catalogued by the repository. |
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| | `content` | string | Full text of the deposited PDF, extracted to Markdown (cleaned — see below). This is the main training text and is multi-KB to multi-MB per row. |
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| | `abstract` | string | Author/editorial abstract (Greek and/or English). May be empty. |
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| | `description` | string | Short descriptive note (often a thesis/programme statement). |
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| | `description_full` | string | Longer descriptive note, where present. |
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| | `information` | string | Cataloguer note, frequently of the form `Διπλωματική εργασία--Πανεπιστήμιο Μακεδονίας, …`. |
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| | `subjects` | string | Subject/keyword terms. |
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| | `creator` | string | Author/creator of the work. |
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| | `contributors` | string | Contributors (supervisor, examination committee, hosting postgraduate programme), `;`-separated. |
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| | `supervisor` | string | Thesis/dissertation supervisor. |
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| | `issue_date` | string | Issue/publication date, usually `YYYY` (sometimes `YYYY-MM`). |
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| | `type` | string | Resource type, e.g. `Electronic Thesis or Dissertation ; Text`, `Musical Score`, `Bachelor's Degree Paper`. |
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| | `publisher` | string | Publisher (predominantly `Πανεπιστήμιο Μακεδονίας`). |
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| | `department` | string | Depositing department / faculty. |
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| | `collection_name` | string | Psepheda collection (typically a specific postgraduate programme). |
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| | `title_alt` | string | Alternative title, where present. |
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| | `rights` | string | **Per-item rights/licence statement — authoritative for licensing.** See the *License* section. |
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| | `relations` | string | Related-item references (mostly empty). |
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| | `handle_url` | string | Canonical DSpace handle landing page for the item. |
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| | `pdf_url` | string | Direct URL to the source PDF on `dspace.lib.uom.gr`. |
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|
|
| **Cleaning & Known Quality Notes** <br>
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| This release is derived from a raw extraction of 14,413 items through a documented, auditable QA pipeline. The raw → released chain is:
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|
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| `raw (14,413)` → drop 98 hallucinated extractions → `(14,315)` → drop 12 English-only documents → **released (14,303)**.
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|
|
| 1. **Removed 98 hallucinated extractions (−0.68%).** On pages the extractor could not read (old scans, music scores, handwriting) it emitted multilingual gibberish — floods of CJK / Arabic / Hebrew / Indic / Georgian / Cherokee glyphs, often injected mid-word. Rows were dropped only when this foreign-script noise was severe (≥30 exotic letters or ≥20 script-mixing junctions, measured on the raw text). **Cyrillic was deliberately excluded** from this rule because it is legitimate in the Slavic/Balkan-studies collections, which are preserved.
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| 2. **Removed 12 genuinely English documents (−0.08%).** Because this is a Greek corpus, documents that are English *as a whole* were dropped — but only when **title, body, and (where present) abstract were all predominantly non-Greek**. This conservative three-signal rule protects the many Greek theses whose bodies are Latin-heavy for legitimate reasons (code listings, mathematics, English citations, music/jazz catalogues).
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| 3. **Text cleaning applied to surviving `content` (formatting only).** HTML entities were unescaped (including a double-escaped layer present in some captured web pages), non-breaking spaces normalized to regular spaces, broken local image placeholders `` removed, runs of 3+ blank lines collapsed, and leading/trailing whitespace stripped. Source-faithful elements were **preserved**: table-of-contents dot leaders, inline `<table>` markup, and all Cyrillic text.
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|
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| Quirks that were intentionally **preserved** (faithful to source): TOC dot-leaders, inline HTML tables, all four description-like fields (`description`, `description_full`, `information`, `abstract`), a small number of embargoed/metadata-only items whose `content` still extracted text, and the original per-item `rights` strings verbatim.
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|
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| **Dataset Statistics** <br>
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| Counts cover the text fields `content + title + abstract` (other columns are bibliographic metadata and are excluded), following the glossAPI convention.
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|
|
| * Records (rows): 14.303
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| * Repository collections: 120
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| * Issue-date coverage: ~1900 – 2026 (concentrated 2005–2025)
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| * Size on disk: 1,87 GB (parquet)
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| * Words: 376.107.060 (whitespace-separated, on `content + title + abstract`)
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| * Tokens: 769.348.015 (`nlpaueb/bert-base-greek-uncased-v1` WordPiece tokenizer, no special tokens, no truncation)
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| * Characters: 2.892.686.626
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|
|
| Per-field breakdown (rows = 14.303):
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|
|
| | Field | Non-empty | Characters | Words | Tokens |
|
| |---|---:|---:|---:|---:|
|
| | `content` | 14.303 | 2.870.226.703 | 372.996.488 | 765.312.500 |
|
| | `abstract` | 11.790 | 21.083.834 | 2.931.401 | 3.799.384 |
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| | `title` | 14.302 | 1.376.089 | 179.171 | 236.131 |
|
|
|
| **License** <br>
|
| **Important: this dataset carries mixed, per-item licensing.** It aggregates self-deposited academic works whose authors each chose their own licence at deposit time. The repository tag for this dataset (`cc-by-nc-nd-4.0`) is a **conservative umbrella** reflecting the source repository's blanket terms; **it is not a uniform grant.** The authoritative licence for any individual record is its own `rights` field.
|
|
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| According to the University of Macedonia Library (`openaccess.lib.uom.gr`): *"Use of all the digital content of the ΨΗΦΙΔΑ collections is personal and for educational, research and private purposes only, **not for commercial purposes**, unless a licence states otherwise."* Bibliographic metadata is provided under **CC BY-NC 3.0 Greece**. Users are instructed to consult the **`Rights`** field of each record.
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|
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| Distribution of the `rights` field across the 14,303 records:
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|
|
| | Rights family | Records | Share |
|
| |---|---:|---:|
|
| | None / unspecified (default: all rights reserved) | 6,406 | 44.8% |
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| | CC BY-NC-ND 4.0 | 2,839 | 19.8% |
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| | CC0 1.0 | 1,564 | 10.9% |
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| | CC BY-ND 4.0 | 745 | 5.2% |
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| | Embargoed (full text not released) | 674 | 4.7% |
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| | CC BY 4.0 | 571 | 4.0% |
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| | CC BY-NC 4.0 | 548 | 3.8% |
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| | Hellenic Parliament (all rights reserved) | 337 | 2.4% |
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| | CC BY-NC-SA 4.0 | 276 | 1.9% |
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| | CC BY-SA 4.0 | 143 | 1.0% |
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| | Law 2121/1993 digitization / bespoke / errors | ~200 | 1.4% |
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|
|
| Practical guidance for downstream users:
|
| - **Filter by the `rights` column** for your use case. Roughly 22% of records carry a CC licence that clearly permits derivatives (CC0, BY, BY-SA, BY-NC, BY-NC-SA); about 25% are explicitly NoDerivatives (ND); about 53% have no open licence stated.
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| - **Do not assume commercial rights.** The repository's default is non-commercial, educational/research use.
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| - **Attribute** the original authors and the University of Macedonia / ΨΗΦΙΔΑ repository, and link back via `handle_url`.
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|
|
| > Source: ΨΗΦΙΔΑ (Psepheda) — Library & Information Centre, University of Macedonia (`dspace.lib.uom.gr`). Copyright in each work remains with its original author(s); see each record's `rights` field.
|
|
|
| **Usage** <br>
|
| This dataset is useful for:
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| - Greek-language NLP and language-model pretraining/adaptation over an **academic / scientific register** (economics, business, informatics, accounting, music, education, social sciences).
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| - Domain-adapted embeddings, terminology extraction, and retrieval/Q&A over Greek postgraduate research.
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| - Long-document modelling (many items are full theses of tens to hundreds of thousands of characters).
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|
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| **Contact** <br>
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| For feedback contact: glossapi.team@eellak.gr
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|
|
