v1 vLLM run specifications
Models, context, prompts, sampling, and decode settings for prompt-v1 baselines
Companion: llm_v2_v3_enhanced_variants.md · persona_prompt_versions.qmd · config/vllm_presets.yaml
This page pins the prompt-v1 digital-twin generation stack used for the four published full-cohort baselines (N = 241 × 5 = 1,205 prompts each). Primary manuscript claims remain on these runs.
1 Models (prompt v1)
| Model | HF id | Role in v1 ranking |
|---|---|---|
| Llama-3.1-8B-Instruct | meta-llama/Llama-3.1-8B-Instruct |
Cautionary transit IP collapse |
| Llama-3.2-3B-Instruct | meta-llama/Llama-3.2-3B-Instruct |
Best group bands / IP MAE among non-collapsed |
| DeepSeek-R1-Distill-Llama-8B | deepseek-ai/DeepSeek-R1-Distill-Llama-8B |
Best pooled group MAE; tier-stable |
| Llama-3.3-70B-Instruct | meta-llama/Llama-3.3-70B-Instruct |
Mode-collapse cautionary case |
Export stamps (where documented): Llama-3.1 20260726_0221; Llama-3.2 …_20260726_0252; DeepSeek …_20260726_0324. Host for 8B/3B/DeepSeek: rogers-gpu-1.discovery.wisc.edu (RTX A5000; fp8 Marlin weight-only where stated).
2 Prompt styling (v1)
| Layer | v1 specification |
|---|---|
| Framing | AI Terrarium / ICA 2026 digital twin: second-person narrative (“You are a …”), not checklist / “adopt this profile” |
| System prompt | Inhabit persona; first-person CA self-report; JSON-only contract with group + interpersonal scores (6–30) and bands (low/moderate/high). Historical v1 system text omitted the later independent-subscale / non-deterministic / mobility-anti-bleed clauses |
| User prompt | Cumulative narrative (demos → employment → geo → transit → full) + fused CA ask |
| Geo | High-precision lat/lon (≈4 decimal) |
| Transit | Full mobility dump including rides-per-day even when frequency was Never |
| Instruction style | Instruct-tuned chat template (tokenizer.apply_chat_template); system + user messages; DeepSeek may emit <think> traces before JSON (post-processed at ingest) |
| JSON constraint | Soft prompt only (“Respond with ONLY a JSON object”); no guided decoding in v1 |
Current tree code implements v2/v3.1-enhanced packaging (signal-first + anti-bleed). Historical v1 wording is preserved in this page and the published baseline write-ups, not as a live --prompt-version switch.
3 Runtime / decode (v1)
Values below are the predict_vllm.py / run_vllm.sh defaults that applied when published launchers omitted sampling flags. Write-ups documented quantisation and throughput for some models but often omitted temperature; treat greedy defaults as the reproducible reconstruction.
| Parameter | v1 value | Notes |
|---|---|---|
temperature |
0.0 | Greedy decode (code default) |
top_p |
1.0 | Nucleus disabled |
repetition_penalty |
1.0 | Off |
seed |
unset | Not reproducible across engines |
max_output_tokens |
256 | CA JSON headroom |
max_model_len (context) |
8192 | Shell / CLI default |
quantization |
fp8 | Documented for 3.1 / DeepSeek; assumed for siblings |
gpu_memory_utilization |
0.9 | |
batch_size / save_freq |
16 / 200 | Checkpoint-resume CSV |
tensor_parallel_size |
1 (shell) / 2 (CLI default) | Published 8B runs used TP=1 on A5000 |
| Guided JSON | false | Prompt-only contract |
Preset name for reconstruction: v1_baseline in config/vllm_presets.yaml.
VLLM_PRESET=v1_baseline ./scripts/run_vllm.sh
# or
python -m inference.predict_vllm --preset v1_baseline ...4 Why these settings matter for RQs
- Greedy + soft JSON recovered valid JSON at 100% for Llama instruct models, but Llama-3.3-70B collapsed to ≈93% constant prior
(18, 12)— parse success ≠ twin success. - Fused transit dump + high-precision geo coincided with Llama-3.1 interpersonal MAE 4.67 → 8.17 and signed error −2.2 → +6.5 (systematic high-IP over-prediction).
- No seed limits exact replay of stochastic siblings; v2/v3 enhanced presets fix seed=42.
Enhanced decode + packaging for future re-runs: llm_v2_v3_enhanced_variants.md.