Using the Omega Index for Evaluating Abstractive Community Detection
Bibliographic record
Abstract
Numerous NLP tasks rely on clustering or community detection algorithms. For many of these tasks, the solutions are disjoint, and the relevant evaluation metrics assume nonoverlapping clusters. In contrast, the relatively recent task of abstractive community detection (ACD) results in overlapping clusters of sentences. ACD is a sub-task of an abstractive summarization system and represents a twostep process. In the first step, we classify sentence pairs according to whether the sentences should be realized by a common abstractive sentence. This results in an undirected graph with sentences as nodes and predicted abstractive links as edges. The second step is to identify communities within the graph, where each community corresponds to an abstractive sentence to be generated. In this paper, we describe how the Omega Index, a metric for comparing non-disjoint clustering solutions, can be used as a summarization evaluation metric for this task. We use the Omega Index to compare and contrast several community detection algorithms.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.019 | 0.090 |
| Meta-epidemiology (narrow) | 0.002 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.020 | 0.009 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.004 | 0.008 |
| Open science | 0.002 | 0.003 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".