{
  "name": "MMT-Bench",
  "release_date": "2026-05-26",
  "subsets": {
    "main": {
      "language": [
        "en"
      ],
      "modalities": [
        "multi_image_start"
      ],
      "task_type": "multiple_choice_qa",
      "score_pipeline": [
        "rule-match",
        "llm-match"
      ],
      "score_protocol": {
        "reference": "VLMEvalKit@vlmeval/dataset/image_mcq.py:81-85,249-318 (MMT-Bench served by ImageMCQDataset.evaluate -> mcq_vanilla_eval; report_acc_MMT at :317-318) + vlmeval/dataset/utils/multiple_choice.py:359-406,475-508 — rule prefetch via can_infer (option letter / unique option-text), GPT extraction fallback, exact letter compare. Official MMT-Bench (OpenGVLab) evaluates via VLMEvalKit.",
        "note": "Official headline aggregation is report_acc_MMT: accuracy grouped by category/l2_category (per-sample scorer yields overall accuracy only). mm-eval publishes the VAL split (3126 rows). lmms-eval mmt uses rule-only MMMU-style parsing (no GPT fallback) — VLMEvalKit protocol preferred as the authors' official harness."
      },
      "prompt_template": "{% for _ in range(n_images) %}<image>{% endfor %}{{ question }}\nOptions:\n{% for k, v in options.items() %}{{ k }}. {{ v }}\n{% endfor %}Please select the correct answer from the options above. ",
      "mapping_from_source": {
        "media": {
          "from": "images",
          "type": "list",
          "min_items": 1,
          "max_items": 23
        },
        "id": {
          "from": "id"
        },
        "question": {
          "from": "question"
        },
        "answer": {
          "from": "answer",
          "optional": true
        },
        "options": {
          "from": "options",
          "optional": true,
          "note": "list source values are normalized to {A,B,...} dict"
        },
        "extra": {
          "source_id": {
            "from": "source_id"
          },
          "category": {
            "from": "category"
          },
          "l2_category": {
            "from": "l2_category"
          },
          "n_images": {
            "from": "n_images"
          }
        },
        "source": {
          "format": "json",
          "url": {
            "val": "https://huggingface.co/datasets/Kaining/MMT-Bench"
          }
        }
      },
      "prompt_template_source": {
        "origin": "official",
        "reference": "https://github.com/EvolvingLMMs-Lab/lmms-eval/blob/main/lmms_eval/tasks/mmt/utils.py#L40-L55 (mmt_doc_to_text — multi-image MCQ with 'Question:/Options:/A./B./Please select the correct answer from the options above. ' format)",
        "notes": "Tier 4: lmms-eval MMT-Bench canonical evaluation prompt."
      }
    }
  }
}