IIIT5Km — IIIT5Km_longform

Rejection-sampled from the IIIT5Km train split. This split holds the long-form items the verifier cannot score, shipped unverified.

rows	30
QA pairs	30
shards	1
accepted / rejected (whole family)	3,893 / 113
accept rate	97.2%
verifier	alnum

How the data was produced

A VLM answers every question at temperature 0 with reasoning enabled. Its answer is compared with the official ground truth by the verifier described below; matches go to IIIT5Km_RS_think and IIIT5Km_RS_nothink, non-matches go to IIIT5Km_rejected with the ground truth preserved.

The question field is byte-identical to the prompt the model actually received, including any appended instruction, so the stored training text and the inference-time input cannot drift apart.

How a match is decided

alnum — scene-text recognition protocol

The standard evaluation protocol for scene-text recognition (IIIT5K, CUTE80, SVT, IC13/15, WordArt, Total-Text): fold case and drop every non-alphanumeric character from both sides, then require an exact match. "HELLO!", "hello" and "Hello." are therefore the same answer.

The prediction is additionally tried as its first line and its first paragraph, so a model that gives the right answer and then explains anyway is not penalised for the explanation.

Second pass: model-as-judge

String verifiers cannot judge free-form answers at all, and they under-credit answers that are correct but differently phrased. Every item the verifier rejected is therefore re-examined by the same VLM in a text-only pass that sees the question, the reference and the candidate — no image, no re-generation, it only grades text that was already produced.

The judge is instructed to compare against the reference and never to solve the question itself, so an answer is not promoted merely because the model believes it is true. It answers CORRECT, WRONG, or UNSURE; numbers must agree, and UNSURE is reserved for references that are themselves unusable or ambiguous. UNSURE is never counted as correct — only a CORRECT verdict moves a row into the accepted splits. WRONG and UNSURE both remain in the rejected split, so an unresolved case is never silently promoted to a pass.

Calibration: run over items the string verifier had already accepted, the judge agreed on 59/60. Spot-checking its overturns shows it discriminates rather than rubber-stamps — it keeps \frac{L}{n} rejected against a reference of \frac{L}{n-1}, and returns UNSURE when the model argues no finite answer exists against a numeric reference.

Schema

• image — HF Image() — renders directly in the dataset viewer
• qa — list of {question, answer, note}
• clean_meta — per-row provenance and the cleaning policy that admitted it
• image_sha256 — content hash of the image

Examples

Three rows taken straight from this split. Images are the original files as stored in the dataset, and long fields are shown in full.

Example 1

field	value
question	Answer in short without any other content.
answer	\tan \angle B A C = \frac { \sin 2 4 } { \cos 2 4 } = \frac { \frac { 2 4 } { 2 5 } } { \frac { 2 } { 2 5 } } = \frac { 2 4 } { 7 }
note	long-form: not judgeable by alnum

Example 2

field	value
question	Answer in short without any other content.
answer	| x - \frac { p _ { n } } { q _ { n } } | \leq \frac { 1 } { q _ { n } q _ { n + 1 } } < \frac { 1 } { q _ { n } ^ { 2 } }
note	long-form: not judgeable by alnum

Example 3

field	value
question	Answer in short without any other content.
answer	\lim _ { x \rightarrow a } \frac { f ( x ) } { g ( x ) } = \lim _ { x \rightarrow a } \frac { f ^ { ' } ( x ) } { g ^ { ' } ( x ) }
note	long-form: not judgeable by alnum

Cleaning applied before rejection sampling

• Provenance check. Each QA item records where it came from; items whose recorded source does not resolve to the image they are attached to are dropped.
• Task purity. The pool's InfinityMM slice assigns samples to a family by image match rather than by dataset origin, which pulls unrelated general-VQA questions into benchmark families. Families where that content measured off-task keep only their genuine benchmark QA.
• Multiple-choice normalisation. Where options had been flattened into prose, they are re-rendered as a lettered block and the reference is rewritten to the bare letter, so the task is well posed and the answer is unambiguous.