Memo: Does DeepSeek-R1-Distill-Llama-8B recover PRCA on prompt v1?
Research memorandum — full-cohort vLLM baseline (Terrarium 5-tier ladder)
Research question: Does deepseek-ai/DeepSeek-R1-Distill-Llama-8B recover group and interpersonal PRCA on prompt-v1 Terrarium tiers better than Llama-3.1/3.2 Instruct ((Binz & Schulz, 2024)) — and is its reasoning-distill format (chain-of-thought then answer) compatible with schema-valid CA JSON at scale?
Formal write-up: docs/llm_baseline_deepseek_r1_distill_v1.md
Cross-model memo: vllm_v1_cross_model_comparison.qmd
1 Answer, Response, + Summary of Results
Full-cohort vLLM run (n = 241; 1,205 prompts; parse ****1202/1205** = 99.8%; fp8 Marlin weight-only; throughput 1.34** samples/s; wall ≈ 450 s; export psych755_vllm_deepseek_r1_distill_llama8b_full_cohort_20260726_0324). Ingest normalizes SentencePiece artifacts and prefers text after </think> before JSON parse.
Short answer: Best pooled group MAE among the three v1 runs (5.22), with the most tier-stable error profile — transit does not induce Llama-3.1’s interpersonal collapse. Interpersonal MAE (5.73) is between Llama-3.2 (5.35) and Llama-3.1 (5.82). Band accuracies sit near chance (group 33.4%, IP 35.4%). Exact match remains rare (~6%). Three prompts failed schema parse (geo/transit/full incomplete rows in the metrics table). Still above Ridge ML floor (~4.49 group MAE).
1.1 Overall vs Llama instruct baselines
Table Table 1 compares DeepSeek-R1-Distill with the Llama instruct baselines.
| Metric (all tiers) | DeepSeek-R1-Distill-8B | Llama-3.2–3B | Llama-3.1–8B |
|---|---|---|---|
| MAE group | 5.22 | 5.51 | 5.92 |
| MAE interpersonal | 5.73 | 5.35 | 5.82 |
| Band group | 33.4% | 52.7% | 28.8% |
| Band interpersonal | 35.4% | 30.0% | 40.2% |
| Parse success | 99.8% | 100% | 100% |
1.2 Metrics by tier
Table Table 2 reports MAE and band metrics by tier.
| Tier | n GT | MAE G | MAE IP | Band G | Band IP | Mean err G | Mean err IP |
|---|---|---|---|---|---|---|---|
| demos | 241 | 5.12 | 5.93 | 31.1% | 32.4% | −0.55 | +1.25 |
| employment | 241 | 5.16 | 5.66 | 31.5% | 36.1% | −0.43 | +1.55 |
| geo | 240 | 5.30 | 5.86 | 33.3% | 32.1% | −1.26 | +0.99 |
| transit | 240 | 5.15 | 5.80 | 36.3% | 35.0% | −0.71 | −0.03 |
| full | 240 | 5.40 | 5.42 | 35.0% | 41.7% | −1.38 | −0.52 |
1.3 RQ verdicts
- RQ1 (employment): Negligible group change; modest IP MAE improvement (−0.27).
- RQ2 (transit): Essentially flat vs demos on both subscales; no IP catastrophe.
- RQ3 (full): Best IP MAE and IP band in this model’s ladder; group MAE slightly worse than demos.
Conclusion. DeepSeek-R1-Distill-Llama-8B is the most robust prompt-v1 continuous scorer for group CA in this trio and the clearest evidence that transit text need not destroy interpersonal recovery. Tradeoffs: slower throughput, rare parse failures, and weaker group-band accuracy than Llama-3.2–3B. Prefer DeepSeek when the scientific claim is about MAE / tier stability; prefer Llama-3.2 when the claim is about coarse group-band classification.
Sources: data/vllm/deepseek-distilled/deepseek_v1.md · data/vllm/deepseek_v1.csv · docs/llm_baseline_deepseek_r1_distill_v1.md · github.com/Exios66/psych755-jjb
2 What questions or uncertainties remain?
Do the three parse failures share a prompt/tier pattern? Does forcing JSON-only decoding (no visible <think>) change MAE? Will v2/v3 packaging preserve DeepSeek’s tier stability while lifting band accuracy toward Llama-3.2’s group-band performance?
3 What other analyses pair with this memo?
Cross-model synthesis: vllm_v1_cross_model_comparison.qmd. Llama baselines: vllm_v1_llama31_8b.qmd, vllm_v1_llama32_3b.qmd.