What this is
- Base model:
unsloth/Qwen2.5-1.5B-Instruct (apache-2.0)
- Finetuning: LoRA (r=16, alpha=16, all attention + MLP projection modules), trained on real
(question, RAG-teacher-answer) pairs generated from the FAA Airplane Flying Handbook via a
real, working retrieval-augmented-generation system -- this repo does not reimplement the
RAG system, it distills its outputs.
- This repo includes both the LoRA adapter (PEFT format) and a Q4_K_M-quantized GGUF for
local serving via Ollama/llama.cpp.
Honest eval results
Evaluated against 8 golden questions (never trained on), judged for correctness/completeness
against reference notes by an independent LLM judge, compared to the stock (non-finetuned)
base model and to the original RAG-teacher system.
Table with columns: Arm, Correctness, Completeness| Arm | Correctness | Completeness |
|---|
| Base (stock unsloth/Qwen2.5-1.5B-Instruct) | 0/8 | 0/8 |
| This finetuned model | 0/8 | 0/8 |
| RAG-teacher (real retrieval + citations) | 0.5-0.75 (varied across real runs) | -- |
The finetuned model did not measurably beat the stock base model. Both scored
0/8 on a strict binary correctness judge, across every real eval
run, including after scaling the training set from 191 to 331 real pairs and retraining from
scratch -- the result did not change, and the specific failure pattern (confidently claiming
coverage of an out-of-scope question) persisted identically across both adapters.
Two plausible causes were tested and ruled out with real controlled experiments, not assumed:
- Quantization: a direct comparison against the pre-quantization fp16 model showed equally
confused (if not worse) answers -- Q4_K_M is not the cause.
- Training data volume: scaling from 191 to 331 real pairs and retraining produced an
identical result -- more data of the same kind did not help.
The qualitative difference that did survive finetuning: this model stayed topically relevant
to aviation on every question, while the stock base model regularly hallucinated unrelated
content (e.g. confusing aviation V-speed terminology with cloud-computing/virtualization
terms). Finetuning changed the model's behavior (answer directly, stay in-domain) without
teaching it precise factual recall -- consistent with LoRA being sample-efficient at behavior
transfer but not at encoding large volumes of new factual knowledge into a small (1.5B
parameter) model without retrieval.
The real, achievable ceiling for this exact judge/question set isn't 100% either -- the
RAG-teacher itself, with real retrieval and citations, only scored 0.5-0.75
correct across real runs (generation isn't fully deterministic even at judge temperature 0.0).
Full per-question answers, methodology, and the diagnostic investigation:
eval report ·
project history ·
learning notes.
Intended use and limitations
Do not use this model as a source of real aviation facts. The measured result above shows
it does not reliably produce correct answers to aviation knowledge questions. This is a
portfolio/research artifact demonstrating a distillation pipeline and its measured limits, not
a production aviation reference. For real FAA Airplane Flying Handbook questions, use the
original RAG system linked above, which is grounded in real, citable source material.
License
apache-2.0, matching the base model (unsloth/Qwen2.5-1.5B-Instruct). This is a
finetuned derivative; no additional restrictions are added.