social-story-gemma4-e2b-v4

On-device social-story generator for the Mystoria iOS app. Gemma 4 E2B Instruct (text-only) with a rank-8 LoRA adapter fused into the base weights and quantized to 4-bit for MLX deployment.

The model generates Carol Gray Social Stories (10.4 methodology) for autistic children from a topic, situation, and target age. It runs fully on-device; no caregiver input leaves the phone.

v4 vs v3

v4 is retrained on a new teacher corpus generated by GPT-5.5 under the production cloud prompt and filtered to Carol Gray 10.4 (4:1 descriptive:coaching ratio and at most one audience-coaching sentence). Training used completion-only loss (mask_prompt: true).

On a 20-prompt evaluation grid (5 ages x 4 topics), scored against the 10.4 Tier-1 rule set with the app's sampler (temperature 0.5, top-p 0.9, repetition penalty 1.15):

Metric	v3 fused 4-bit	v4 fused 4-bit
JSON valid	90%	100%
Tier-1 pass (10.4)	40%	85%
Audience-coaching cap (<= 1)	40%	85%

Training

• Base: mlx-community/Gemma4-E2B-IT-Text-int4
• LoRA: rank 8, scale 16, 26 layers, attention projections only
• 2500 iterations, learning rate 1e-5, effective batch 4, mask_prompt: true
• Corpus: 1604/200/202 train/valid/test, 10.4-filtered

Intended use

Educational children's-app content generation. Not a clinical tool. Outputs should be reviewed by a caregiver before use.