# ETD-ODv2: AI-Aided Annotation and Dataset for Layout Analysis of Long Documents

> Research notes on ETD-ODv2, a 62K-page dataset for layout analysis of scanned theses and dissertations, with an AI-aided annotation framework to reduce labeling time and class imbalance.

- Authors: Hunter Heidenreich
- Published: 2026-03-13
- Paper: Published (WWW '23) <https://doi.org/10.1145/3543873.3587609>
- Dataset: ETD-ODv2 (dataset + code) <https://github.com/Opening-ETDs/ETD-OD>
- Source: Bevaya Labs, <https://labs.bevaya.ai/>

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## TL;DR

Ahuja et al. propose an AI-aided annotation framework that uses a pre-trained object detection model to generate weak bounding-box labels, which human annotators then verify and correct. They release ETD-ODv2, a 62K-page, 300K-annotation dataset for layout analysis of electronic theses and dissertations (ETDs), including scanned documents and targeted pages for minority element classes. Models trained on the combined dataset achieve a mAP@0.50 of 0.886, up from 0.774 with digital-only data.

## What kind of paper is this?

**Dominant:** $\Psi\_{\text{Resource}}$ . The headline contribution is ETD-ODv2, a new dataset that extends ETD-OD with 16.8K scanned pages and 20.2K AI-aided annotated pages. The annotation framework is in service of producing this resource.

**Secondary:** $\Psi\_{\text{Method}}$ . The AI-aided annotation scheme (pre-trained model generates weak labels, optional class-based filtering, human verification) is a methodological contribution, though it is relatively straightforward and primarily described as a pipeline rather than an algorithmic novelty.

## What is the motivation?

Layout analysis of long scholarly documents (theses, dissertations) faces three specific challenges:

1. **Annotation cost:** Labeling bounding boxes on document pages is slow. No LaTeX source is available for scanned documents, so automatic annotation methods (used by PubLayNet, DocBank) do not apply.
2. **Scanned document noise:** Legacy ETDs were typewritten, microfilmed, and/or scanned, introducing noise, low resolution, dilated/eroded text, and handwritten elements that cause models trained on clean digital PDFs to underperform.
3. **Class imbalance:** Certain elements (title, author, algorithm, equation number) appear on only a handful of pages per document, leading to severe frequency skew in page-level datasets.

The prior ETD-OD dataset (Ahuja et al., 2022) addressed digital ETDs only and suffered from the imbalance problem. ETD-ODv2 is designed to fill both gaps.

## What is the novelty?

### AI-Aided Annotation Framework

The framework has four stages:

1. **Dataset sampling:** Sample unlabeled ETDs from open-access institutional repositories and split into page images.
2. **Weak label generation:** Run a YOLOv7 model (pre-trained on ETD-OD + a small scanned seed set) on each page to produce predicted bounding boxes and class labels.
3. **Optional filtering:** Use predicted labels to select pages likely to contain minority-class elements (e.g., title, algorithm, equation number). This directly addresses class imbalance by over-sampling rare pages.
4. **Human verification and correction:** Annotators review model predictions, keeping correct ones and fixing incorrect/missing boxes.

The key practical insight is that even a model trained on limited, imbalanced data produces enough correct predictions to substantially reduce annotation effort (2-3$\times$ speedup).

### ETD-ODv2 Dataset

The dataset extends ETD-OD with two new subsets:

- **Scanned subset:** ~16.8K pages from 100 scanned theses/dissertations, manually annotated by 5 undergraduates with author review. Captures noise, low resolution, and handwritten elements absent from digital ETDs.
- **AI-aided subset:** ~20.2K pages from ~1,200 documents (scanned + digital), filtered to over-represent 12 minority element classes, then verified/corrected by 4 annotators.

Combined with the original ETD-OD digital subset (25K pages), the full dataset contains:

- **62,043 page images**
- **300,388 bounding-box annotations**
- **24 object categories** (metadata elements like title/author/degree, structural elements like paragraph/section/chapter title, and content elements like equation/table/figure/algorithm)

## What experiments were performed?

### Annotation Time Study

Four annotators each labeled ~500 pages under three conditions:

| Setting | Description |
| :--- | :--- |
| **No Model** | Classical annotation; no bounding boxes shown |
| **AI-Aided-v1** | YOLOv7\_base model generates initial boxes |
| **AI-Aided-v2** | YOLOv7 fine-tuned on 10K additional AI-aided pages generates boxes |

Average time per page decreased by 2-3$\times$ with model assistance (AI-Aided-v1 vs. No Model). AI-Aided-v2 further reduced time beyond v1, confirming that better models yield more useful suggestions.

### Object Detection Performance

YOLOv7 was trained on four dataset configurations and evaluated on a held-out test set of 9,353 pages (44,331 objects) spanning digital, scanned, and AI-aided sources:

| Training Data | Images | Objects | mAP@0.50 | mAP@0.50:0.95 |
| :--- | :--- | :--- | :--- | :--- |
| Digital only | 21,313 | 85,540 | 0.774 | 0.573 |
| Scanned only | 14,204 | 53,834 | 0.596 | 0.356 |
| Digital + Scanned | 35,517 | 139,374 | 0.832 | 0.590 |
| Digital + Scanned + AI-Aided | 52,690 | 256,057 | **0.886** | **0.655** |

Metrics: COCO-style AP@0.50 and AP@0.50:0.95.

## What are the outcomes/conclusions?

**Key results:**

- The AI-aided annotation framework reduces per-page annotation time by 2-3$\times$ compared to manual labeling, and the benefit increases as the assisting model improves.
- Adding scanned and AI-aided data to the training set improves mAP@0.50 from 0.774 (digital-only) to 0.886, an 11.2 percentage point gain.
- Minority classes benefit the most from targeted annotation. Algorithm detection jumps from 0.368 to 0.665 AP@0.50 (a ~30 pp gain); Degree from 0.524 to 0.732 (~21 pp).
- The filtering step does not hurt majority-class performance; in fact, pages selected for minority elements also contain majority elements like paragraphs, providing additional training signal across all classes.

**Limitations and open questions:**

- The annotation framework relies on an existing pre-trained model. If the seed model is very poor (e.g., for a completely new document domain), the weak labels may not provide enough benefit to justify the pipeline overhead.
- Inter-annotator agreement is not reported. Although each scanned sample received a second review by an author, no formal IAA metric (e.g., Krippendorff's Alpha) is provided.
- The test set was constructed from the same sources as the training data (ETD-OD + ETD-ODv2), so generalization to non-ETD long documents (books, legal filings, government reports) is untested.
- Only YOLOv7 was evaluated as the object detection model. The authors acknowledge this but do not test other architectures (e.g., Faster R-CNN, DETR variants) to confirm the gains are model-agnostic.
- The paper does not discuss annotation quality differences across the five undergraduate annotators or the four AI-aided annotators.
- The GitHub repository does not specify a license, making the legal terms for dataset use unclear despite the paper being published under CC-BY-NC-4.0.

## Reproducibility

### Models

- **YOLOv7** used as the detection model throughout (both for AI-aided annotation and final evaluation).
- YOLOv7\_base: trained on ETD-OD + ~2K scanned pages. Specific hyperparameters not detailed.
- YOLOv7\_v2: YOLOv7\_base fine-tuned on an additional 10K AI-aided pages.
- The paper's conclusion claims "the code, datasets, and pre-trained models discussed in this paper are available at" the GitHub repository. However, the repo contains only a README.md file with a three-sentence description. No code, data files, or model weights are present. The repo was last updated October 2022 and has no license file.

### Algorithms

- Training procedure details (learning rate, optimizer, epochs, augmentation) are not reported.
- The AI-aided annotation pipeline uses pylabel (open-source bounding box widget) integrated with the pre-trained model.
- Roboflow was used as the annotation platform for the scanned subset.

### Data

- **Source:** ETDs from open-access US institutional repositories, uniformly sampled. Specific repositories are not enumerated.
- **Scanned subset:** 100 documents, ~16.8K pages. Annotated by 5 undergraduates, reviewed by an author.
- **AI-aided subset:** ~1,200 documents, ~20.2K pages. Filtered for 12 minority element classes. Annotated/corrected by 4 annotators.
- **Digital subset:** From ETD-OD (Ahuja et al., 2022), ~25K pages.
- **Object categories:** 24 classes compatible with ETD-OD.
- Code and data are said to be available at https://github.com/Opening-ETDs/ETD-OD. However, the repository contains only a README.md and no actual code, data, or model files. Last updated October 2022.

### Evaluation

- Metrics: COCO-style mAP@0.50 and mAP@0.50:0.95 (standard).
- Test set: 9,353 pages / 44,331 objects, sampled from all three subsets (digital, scanned, AI-aided).
- Only YOLOv7 is used, limiting the generalizability of the performance comparison.
- No error bars, significance tests, or multi-run statistics are reported.
- No cross-dataset evaluation (e.g., DocLayNet, PubLayNet).

### Hardware

- Not reported. No mention of GPU type, training time, or inference speed.

## BibTeX

```bibtex
@inproceedings{ahuja2023etdodv2,
  author    = {Ahuja, Aman and Dinh, Kevin and Dinh, Brian and Ingram, William A. and Fox, Edward A.},
  title     = {A New Annotation Method and Dataset for Layout Analysis of Long Documents},
  booktitle = {Companion Proceedings of the ACM Web Conference 2023},
  year      = {2023},
  pages     = {835--841},
  publisher = {ACM},
  doi       = {10.1145/3543873.3587609},
}
```


