adaptmmbench-eval
AdaptMMBench: Benchmarking Adaptive Multimodal Reasoning for Mode Selection and Reasoning Process — Zhang et al. (2026) (arXiv:2602.02676, 2026)
What this evaluates
Evaluates Vision-Language Models' ability to dynamically select between text-only and tool-augmented reasoning modes, and assesses the quality, efficiency, and final accuracy of their reasoning processes across multimodal domains.
Datasets
- AdaptMMBench — total 1300; splits: test (1300)
Metrics
Accuracy(primary) — range: [0, 1]- Percentage of correctly answered questions across all domains and reasoning modes. Calculated as the number of correct predictions divided by the total number of samples.
MCC— range: [-1, 1]- Matthews Correlation Coefficient measuring the correlation between a model's adaptive mode selection (text vs. tool) and task difficulty/correctness. Computed as (TPTN - FPFN) / sqrt((TP+FP)(TP+FN)(TN+FP)(TN+FN)).
Input / output format
Input: Multimodal prompts containing images and text questions, formatted with mode-specific instructions (text-only, adaptive, or oracle tool-augmented).
Output: Final answer prediction, plus optional intermediate reasoning steps and tool calls (for adaptive mode).
Scoring recipe
def compute_accuracy(predictions, golds):
correct = sum(1 for p, g in zip(predictions, golds) if p == g)
return correct / len(golds)
def compute_mcc(pred_mode, gold_mode, pred_acc, gold_acc):
tp = sum(1 for p, g, pa, ga in zip(pred_mode, gold_mode, pred_acc, gold_acc) if p==g and pa==ga)
tn = sum(1 for p, g, pa, ga in zip(pred_mode, gold_mode, pred_acc, gold_acc) if p!=g and pa!=ga)
fp = sum(1 for p, g, pa, ga in zip(pred_mode, gold_mode, pred_acc, gold_acc) if p!=g and pa==ga)
fn = sum(1 for p, g, pa, ga in zip(pred_mode, gold_mode, pred_acc, gold_acc) if p==g and pa!=ga)
denom = math.sqrt((tp+fp)*(tp+fn)*(tn+fp)*(tn+fn))
return (tp*tn - fp*fn) / denom if denom > 0 else 0.0
Common pitfalls
- Confusing adaptive reasoning accuracy with oracle accuracy, as oracle represents an upper-bound with perfect tool invocation rather than actual model behavior.
- Assuming fewer reasoning steps or tool calls automatically imply better efficiency, since token consumption does not linearly correlate with step count.
- Applying process-level metrics (key step coverage, tool effectiveness) to closed-source models, whose intermediate reasoning traces are inaccessible.
Evidence (verbatim from paper)
As shown in Table[1] and Table[3], mode selection capability does not exhibit a strong correlation with final task accuracy. For example, AdaptVision achieves a relatively modest accuracy, yet demonstrates strong mode selection behavior with an MCC of 0.17, outperforming all other models trained on Qwen2.5-VL-7B backbones. In contrast, GPT-5 attains the highest MCC of 0.41, demonstrating good mode selection capability.
Citation
@misc{zhang2026adaptmmbench,
title={AdaptMMBench: Benchmarking Adaptive Multimodal Reasoning for Mode Selection and Reasoning Process},
author={Zhang et al. (2026)},
year={2026},
note={arXiv:2602.02676}
}
- arXiv: 2602.02676