Memo: Does DeepSeek-R1-Distill-Llama-8B recover PRCA on prompt v1?

Research memorandum — full-cohort vLLM baseline (Terrarium 5-tier ladder)

Author

Jack J. Burleson

Published

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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.

Table 1.. DeepSeek-R1-Distill tier-level performance.
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.

Table 2.. Tier / n GT / MAE G.
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.

References

Binz, M., & Schulz, E. (2024). Turning large language models into cognitive models. Proceedings of the Twelfth International Conference on Learning Representations. https://doi.org/10.48550/arXiv.2306.03917