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name: scienceclaw-benchmark-for45 description: "Use when a task gives small culturally specific images with language metadata (Indigenous languages of the Americas) and a few captioned training examples per language, and asks for one caption string in the item's own language per image, scored by mean sentence chrF++ against the reference captions (AmericasNLP 2026 cultural image captioning; corresponds to FoR45 of the companion ScienceClaw-Eval benchmark)." metadata: { "openclaw": { "emoji": "📊" } }

Image captioning for low-resource Indigenous languages

Task. Input: evaluation items (language, ISO 639-3 code, culture) with uint8 RGB images (e.g. 64x64x3), and visible training rows (caption, iso_lang, has_image, images; some rows are caption-only). Deliverable: a list of non-empty strings, one per item, in that item's language (captions.fit_predict caps strings at 1000 characters; follow what the task declares).

Quality. Mean sentence chrF++, higher is better: sacrebleu CHRF(word_order=2) (character 1-6-grams, word 1-2-grams, beta 2, case-sensitive, 0-100) against the reference caption. Baseline: the per-language medoid of the visible training captions.

Tools.

• from scilib import captions: chrf, mean_chrf (operator caption_chrf_score), medoid (caption_medoid), consensus_caption (caption_consensus_string), mbr_caption (caption_mbr_clauses), by_language, fit_predict(train_rows, items, method="consensus"|"mbr"|"medoid") (one string per language, from that language's captions only). Estimate a strategy on unseen captions with loo_score / loo_compare / loo_lengths (operator caption_holdout_chrf_estimate), setting n_train to the real training size.
• from scilib import clip_retrieval: available(), provenance(), encode_images (image_embedding_clip), retrieve_captions(train_rows, train_images, eval_items, eval_images, k=1, selection="nearest"|"caption_medoid", fallback=...) (image_caption_retrieval_clip): same-language cosine nearest-neighbour caption lookup; caption-only rows are skipped.
• Weights open_clip_vit_b32 (OpenAI CLIP ViT-B/32 via open_clip; needs torch). Check with scienceclaw_tools(operation=weights) and clip_retrieval.available(); nothing downloads implicitly; verify the licence. Disclose its use: it is an external pretrained encoder that sees no captions or labels.

Routes. (1) Language-level caption: medoid, or a consensus/MBR string maximising mean chrF++ against the language's pool. (2) Image-conditioned retrieval, optionally k>1 with selection="caption_medoid". With few captions per language, retrieval can score below the medoid; choose by leave-one-out chrF++ on the training rows.

Rules.

• Never pool captions across languages. retrieve_captions returns "" for a language without a captioned image, so pass fallback= (e.g. that language's medoid).
• Use no target captions. Consensus and MBR strings optimise n-gram overlap and are not grammatical; say so in the report.
• One string per item, input order. Do not claim image understanding from pixel statistics.