Delucionqa Eval

delucionqa-eval

DelucionQA: Detecting Hallucinations in Domain-specific Question Answering — Sadat et al. (2023) (arXiv:2312.05200, 2023)

What this evaluates

This benchmark evaluates a model's ability to detect hallucinations in domain-specific question answering systems that use retrieval-augmented generation. It probes whether models can correctly identify when a generated answer contradicts or goes beyond the provided retrieved context, often due to over-reliance on pre-trained knowledge or incomplete retrieval.

Datasets

• DelucionQA — total ?; splits: train (-1), dev (-1), test (-1); repo https://github.com/boschresearch/DelucionQA

Metrics

• Macro F1 (primary) — range: percent
  • The unweighted mean of the F1 scores for each class (hallucination and non-hallucination). F1 is calculated as 2 * (precision * recall) / (precision + recall) for each class, then averaged across classes.

Input / output format

Input: A question and the retrieved context (retrieval result).

Output: A binary label indicating whether the generated answer contains a hallucination or is faithful to the context.

Scoring recipe

def compute_macro_f1(predictions, gold_labels):
    classes = ['hallucination', 'non_hallucination']
    f1_scores = []
    for cls in classes:
        tp = sum(1 for p, g in zip(predictions, gold_labels) if p == cls and g == cls)
        fp = sum(1 for p, g in zip(predictions, gold_labels) if p == cls and g != cls)
        fn = sum(1 for p, g in zip(predictions, gold_labels) if p != cls and g == cls)
        precision = tp / (tp + fp) if (tp + fp) > 0 else 0
        recall = tp / (tp + fn) if (tp + fn) > 0 else 0
        f1 = 2 * precision * recall / (precision + recall) if (precision + recall) > 0 else 0
        f1_scores.append(f1)
    return sum(f1_scores) / len(f1_scores)

Common pitfalls

• Data leakage occurs if the same question appears in multiple splits; the protocol requires each unique question to be assigned to exactly one split.
• Simple keyword matching or sentence-level cosine similarity fails to capture one-to-many or many-to-one semantic mappings between context sentences and answer sentences.
• Reporting accuracy instead of Macro F1, which masks class imbalance or uneven performance across hallucination types.

Evidence (verbatim from paper)

The best-performing model SIM-OVERLAP achieves a Macro F1 of only 71.1% on the unseen test set. This indicates that DELUCIONQA presents a challenging new task with substantial room for future improvement. From Table 4, we also notice that there are fluctuations in performance across the three splits (train/dev/test) of the dataset. Recall that while randomly dividing the data into multiple splits, we ensure that each unique question ends up in a single split (to avoid data leakage).

Citation

@misc{sadat2023delucionqa,
  title={DelucionQA: Detecting Hallucinations in Domain-specific Question Answering},
  author={Sadat et al. (2023)},
  year={2023},
  note={arXiv:2312.05200}
}

• arXiv: 2312.05200