SchemaForge V3 — Distilled MiniCPM5-1B (V3 best checkpoint, iteration 2)

This is a public research/development checkpoint from the SchemaForge V3 phase. It is NOT the project's release checkpoint — V2-FINAL (models/schemaforge-v2-distilled-minicpm5-1b/) is the recommended deployment choice — and its hybrid field F1 (0.6745) sits -0.0082 below V2-FINAL (0.6827) on the 72-record eval. It is published because it is the best of V3's four iterations and demonstrates the project's primary improvement: missing_field's share of failures dropped to 52.3%, the lowest measured across V2 and V3. All training and evaluation compute was contributed by the AMD AI Developer Program on an AMD Instinct MI300X (192GB, ROCm). See SchemaForge V3 whitepaper, the V3 findings note (iterations 1-4), and logs/V3_TRAINING_FAILURES.md for the full iteration history.

What this is

A student checkpoint (openbmb/MiniCPM5-1B, ~1.04B params) sequence-level knowledge-distilled from a google/gemma-4-31B teacher for JSON/structured extraction across 12 document schemas (invoice, receipt, resume, contract, support ticket, medical note, insurance claim, CRM record, email, conversation, form, knowledge-graph triple) — the same architecture and pipeline as the SchemaForge V2 release checkpoint (models/schemaforge-v2-distilled-minicpm5-1b/, prepared for publication). V3's goal is to close missing_field (omission), the dominant failure category across every V2 configuration measured (55-62% of all failures). This checkpoint is the best of V3's four iterations: the first change to help since V2 iterations 13/15, it cut missing_field's share of failures to 52.3% — the lowest measured in V3 — by stopping training one epoch earlier under a larger, fuzzy-gate-admitted corpus.

Why this checkpoint, specifically

V3 ran four iterations (full history in logs/V3_TRAINING_FAILURES.md; summary in docs/FINDINGS_V3_ITERATIONS_1_4.md):

• V3 iter 1 (3 epochs, strict gate, 2157/3600 admitted): corpus scale-up n=75→100 hurt (hybrid F1 0.6827→0.6581), isolating "total training steps, not corpus size" as the mechanism.
• V3 iter 2 (this checkpoint) (2 epochs, fuzzy gate, 2691/3600 admitted): F1 recovered to 0.6745, missing_field share down to 52.3% — best-in-V3 on every headline metric.
• V3 iter 3 (1 epoch, same corpus): 0.6597 — underfits; completes the epoch sweep 1/2/3 → 0.6597/0.6745/0.6581, confirming 2 epochs as the optimum.
• V3 iter 4 (LR=1e-5, 2 epochs, same corpus): 0.6671 — under-trains; brackets LR=2e-5 as the optimum.

The recipe grid is now bracketed: 2 epochs at LR=2e-5 is the confirmed optimum — V2/V3's default recipe was already near-optimal for this corpus. This checkpoint sits at that optimum, produced by the fully deterministic pipeline (greedy teacher labels, fixed seed, verified checkpoint backup), so its score is a stable, reproducible measurement. It does not, however, beat the release V2-FINAL (prepared for publication) baseline on the comparable eval — which is exactly why it is published as a research checkpoint, not the project's release checkpoint.

Training data

• 3600-record corpus generated at n=100/schema/severity (data/corpus_v3_iter1.jsonl), same generation command, operator mix, and seed as V2's corpus, scaled up from n=75.
• Iteration 2's attempted fresh teacher generation wedged (deadlock at batch 208/900, busy-spin >1h, killed). Because teacher generation is deterministic (greedy, temperature=0.0), the saved iteration-1 raw outputs are byte-identical to a fresh run — so the admission gate was re-run on iter-1's saved rejections (data/teacher_dataset_rejections_v3iter1_bak.json, 1443 records) with fuzzy_support=True (threshold 0.85) by src/09_recover_fuzzy.py on CPU, recovering 534/1443 (37%) → 2691/3600 admitted (25.2% rejected vs 40.1% under the strict gate). Training dataset: data/teacher_dataset_v3iter2.json.
• 2 epochs, sequence-level cross-entropy distillation (no cross-tokenizer logit KL — invalid in an earlier project phase, dropped). Greedy teacher decoding (temperature=0.0) throughout.

Results

On the 72-record held-out eval set spanning all 12 schemas (including the 3 held-out ones), data/eval_holdout.jsonl:

The hybrid system again beats both individual systems on every metric simultaneously — V3 does not re-test this architectural claim, it optimizes the model's contribution to it. missing_field share of failures: 52.3% (196/375), the lowest measured in V3 and the first V3 configuration to move it below V2's 55-62% band — the intended V3 target, though not yet enough to beat V2-FINAL overall.

Corroboration on the 288-record eval (data/eval_holdout_v2.jsonl): hybrid field F1 0.6742 (precision 0.7169, recall 0.6363, hallucination rate 0.0324, schema validity 0.8715, missing_field_rate 0.1207) — consistent with the 72-record readout.

Comparison to the V2 release checkpoint: 72-rec hybrid field F1 0.6745 vs 0.6827 (V2-FINAL, iteration 15) — -0.0082. This checkpoint does not beat the release checkpoint on the comparable eval. That is the explicit reason V2-FINAL, not this checkpoint, is the recommended deployment checkpoint (checkpoint_used_for_huggingface_upload was recorded as false at eval time, prior to this publication decision).

Known limitations

• Below the release checkpoint (V2-FINAL, prepared for publication) on the comparable 72-record eval (-0.0082): archived for reproducibility of V3's results, not for deployment.
• missing_field (omission) remains the dominant failure category — 52.3% share here, V3's confirmed best. The total-training-steps mechanism improved it but did not close it.
• Model-alone field F1 (0.4803) remains near the un-distilled base model's zero-shot level: the distillation's value is realized through the hybrid architecture, not as a standalone extractor — same caveat as the V2 card.
• V2 limitations carry forward: confidence output needs post-hoc temperature scaling (raw mean-token confidence measures badly overconfident); no hybrid escalation policy to a frontier LLM is implemented; incorrect_normalization has never fired in any measured eval set.

Usage

from transformers import AutoModelForCausalLM, AutoTokenizer

tokenizer = AutoTokenizer.from_pretrained("<this-repo>")
model = AutoModelForCausalLM.from_pretrained("<this-repo>", trust_remote_code=True)

prompt = (
    "Extract the following fields as JSON from the text below. Schema: invoice.\n"
    "Fields to extract: line_items[].description, vendor_name.\n"
    "Text:\nINVOICE #INV-1001. Vendor: Acme Supply Co. ...\n"
    "JSON Output:"
)
inputs = tokenizer(prompt, return_tensors="pt")
out = model.generate(**inputs, max_new_tokens=512, do_sample=False)
print(tokenizer.decode(out[0][inputs["input_ids"].shape[1]:], skip_special_tokens=True))

For production use, run the release V2-FINAL (prepared for publication) checkpoint behind the deterministic pre-pass (schemaforge/deterministic/) and merge with schemaforge/hybrid/pipeline.py's merge_prediction — do not use this checkpoint in production (it underperforms V2-FINAL). The prompt format (schema name + explicit residual field list from the schema's semantic_fields minus whatever the deterministic pass already resolved) must match training; see src/08_hybrid_eval.py's build_prompt in the source repository for the exact template.

Training/compute

Compute acknowledgment: all training and evaluation for this checkpoint was contributed by the AMD AI Developer Program, on an AMD Instinct MI300X (192GB VRAM) with ROCm 7.0.2 / PyTorch 2.11.0.dev+rocm7.0. This checkpoint: 2 epochs × 1346 steps = 2692 total gradient updates; epoch-mean losses 0.0486 / 0.0162 (near-zero-loss plateau by epoch 2, as in every run); LR 2e-5, batch_size 2, AdamW, cosine schedule, bf16, seed 42.

Checkpoint identity

• model.safetensors sha256: c1b51015b12091fd8b71bbae2c9fc16e2091a408e32d15f2c752242bf2227dfb
• Training run: v3-iter2-20260811T0228Z (see experiments/v3-iter2-20260811T0228Z/manifest.json for full machine-readable provenance)
• Git commits: a848a7c (2-epoch retrain; dataset recovery landed at a8be53d)
• Published 2026-08-11 as a public research checkpoint (huggingface.co/arrochi112/schemaforge-v3-distilled-minicpm5-1b); V2-FINAL remains the recommended release/deployment checkpoint (checkpoint_used_for_huggingface_upload was recorded as false at eval time, prior to this publication decision)

Source repository

See the SchemaForge GitHub repository for the full pipeline (schema registry, deterministic pre-pass, hard-example generator, teacher-validation gate, evaluation harness, calibration module, failure-category classifier, hybrid routing), the V2/V3 whitepapers, all experiment manifests, and evidence graphs.