Multimodal benchmarks are specialized by dimension: MMBench for general ability, MMMU for academic reasoning, POPE for hallucination — each with its own question format and metrics.
MMBench: 30 abilities across 16 dimensions (~3000 MCQs) covering perception/cognition/knowledge, with a strict "output only the option letter" format to avoid open-generation parsing ambiguity; the metric is MCQ accuracy
Acc=N1∑i=1N1[y^i=yi];
MMMU: college-level multidisciplinary questions (30+ subjects across arts/business/science/engineering, 11.5K items) designed so that "visual information is necessary" (no-image performance ≈ 25% chance), testing perception + knowledge + reasoning jointly;
POPE (Polling-based Object Probing Evaluation): object-presence probing — asks "Is there a [object] in the image?" for each candidate object; positives are objects truly present, negatives are absent objects in three difficulty tiers (random / popular / adversarial); metrics are binary precision/recall/F1:
F1=P+R2⋅P⋅R,P=TP+FPTP,R=TP+FNTP
plus the yes-ratio (fraction of Yes answers) capturing overall hallucination tendency. Others in common use: ChartQA (numeric reasoning), TextVQA/DocVQA (OCR), ScienceQA (scientific figures), HallusionBench/MMHal-Bench (hallucination + reasoning, the latter scored by LLM-as-judge over multiple dimensions).