PhyX-OE#

Overview#

PhyX is the first large-scale benchmark for physical reasoning in realistic, visually grounded scenarios. This is its open-ended variant: no options are shown, so the model has to derive the answer of a university-level physics problem from the figure and state it.

Task Description#

Task Type: Visual open-ended physics problem solving
Input: A figure plus the problem description and question
Output: A step-by-step derivation ending in the final answer (value with unit or a formula)
Domain: University-level physics (mechanics, electromagnetism, thermodynamics, wave/acoustics, optics, modern physics)

Key Features#

3,000 university-level problems (test) over 6 core domains and 25 sub-domains, each domain exposed as its own subset; eval_split='test_mini' selects the official 1,000-problem testmini set.
Every problem is grounded in a figure that carries information the text does not restate, so the model must combine visual cues with implicit physical laws.
6 reasoning types are represented (physical model grounding, multi-formula, spatial relation, numerical, predictive and implicit condition reasoning).
Uses the default Text-DeRedundancy input style of the paper: the simplified problem description plus the question, with the figure attached.
The official prompt is reproduced verbatim, including its request for step-by-step reasoning, so scores stay comparable with the published numbers.

Evaluation Notes#

Primary metric: acc, mean over problems, reported overall and per domain.
The final answer is read from \boxed{...}, else from a ‘final answer:’ / ‘correct answer:’ statement, else the whole reply is compared. A reply truncated before its answer therefore scores 0 for reasons unrelated to physics ability; give the model a generous generation_config.max_tokens.
Answers are free-form values with units, so an LLM judge is used by default (the official recommendation): set judge.strategy='auto' or 'llm' and provide judge.models. The judge is only consulted when the answer does not already match as a string.
judge.strategy='rule' falls back to the official string-level mode, which understates accuracy because equivalent spellings (0.5 m vs 50 cm) do not match literally.
Figures are sent inline as base64 and the largest is ~5 MB; set max_image_bytes in dataset_args if the served model enforces a smaller per-image limit.
Resources: Paper | GitHub | Project page

Properties#

Property	Value
Benchmark Name	`phyx_oe`
Dataset ID	evalscope/PhyX
Paper	Paper
Tags	`MultiModal`, `QA`, `Reasoning`
Metrics	`accuracy`
Default Shots	0-shot
Evaluation Split	`test`

Data Statistics#

Metric	Value
Total Samples	3,000
Prompt Length (Mean)	364.68 chars
Prompt Length (Min/Max)	93 / 1874 chars

Per-Subset Statistics:

Subset	Samples	Prompt Mean	Prompt Min	Prompt Max
`mechanics`	550	356.92	124	1273
`electromagnetism`	550	326.73	107	1032
`thermodynamics`	500	390.86	93	1174
`waves_acoustics`	500	379.95	101	1731
`optics`	500	361.15	109	1215
`modern_physics`	400	380.12	106	1874

Image Statistics:

Metric	Value
Total Images	3,000
Images per Sample	min: 1, max: 1, mean: 1
Resolution Range	215x46 - 5712x4953
Formats	jpeg, png

Sample Example#

Subset: mechanics

{
  "input": [
    {
      "id": "508a6723",
      "content": [
        {
          "image": "[BASE64_IMAGE: png, ~35.6KB]"
        },
        {
          "text": "A patient with a dislocated shoulder is put into a traction apparatus as shown in figure. The pulls $\\vec{A}$ and $\\vec{B} must combine to produce an outward traction force of 12.8 N on the patient’s arm. How large should these pulls be? Please answer the question with step by step reasoning."
        }
      ]
    }
  ],
  "target": "7.55N",
  "id": 0,
  "group_id": 0,
  "metadata": {
    "index": "0",
    "category": "Mechanics",
    "subfield": "Statics",
    "reasoning_type": [
      "Spatial Relation Reasoning"
    ]
  }
}

Prompt Template#

No prompt template defined.

Usage#

Using CLI#

evalscope eval \
    --model YOUR_MODEL \
    --api-url OPENAI_API_COMPAT_URL \
    --api-key EMPTY_TOKEN \
    --datasets phyx_oe \
    --limit 10  # Remove this line for formal evaluation

Using Python#

from evalscope import run_task
from evalscope.config import TaskConfig

task_cfg = TaskConfig(
    model='YOUR_MODEL',
    api_url='OPENAI_API_COMPAT_URL',
    api_key='EMPTY_TOKEN',
    datasets=['phyx_oe'],
    dataset_args={
        'phyx_oe': {
            # subset_list: ['mechanics', 'electromagnetism', 'thermodynamics']  # optional, evaluate specific subsets
        }
    },
    limit=10,  # Remove this line for formal evaluation
)

run_task(task_cfg=task_cfg)