soup/soup_cli/eval/forgetting.py

122 lines
4.4 KiB
Python

"""Catastrophic forgetting detection (Part G of v0.25.0).
Runs lightweight mini benchmarks against a model during training and flags
significant drops in general-knowledge accuracy from the pre-training baseline.
"""
from __future__ import annotations
from dataclasses import dataclass
from typing import Callable, Literal, Optional
MiniBenchmark = list[dict[str, str]]
# ---------------------------------------------------------------------------
# Built-in mini benchmarks (kept intentionally small — expand to 100 in prod)
# ---------------------------------------------------------------------------
MINI_MMLU: MiniBenchmark = [
{"question": "What is 2 + 2? (A) 3 (B) 4 (C) 5", "answer": "B"},
{"question": "The capital of France is: (A) London (B) Berlin (C) Paris", "answer": "C"},
{"question": "Water freezes at: (A) 0C (B) 50C (C) 100C", "answer": "A"},
{"question": "Photosynthesis uses: (A) oxygen (B) carbon dioxide (C) nitrogen", "answer": "B"},
{"question": "Atomic number of hydrogen is: (A) 1 (B) 2 (C) 3", "answer": "A"},
]
MINI_COMMON_SENSE: MiniBenchmark = [
{
"question": "If it is raining, you should bring a: (A) hat (B) umbrella (C) fan",
"answer": "B",
},
{"question": "You eat breakfast in the: (A) morning (B) evening (C) night", "answer": "A"},
{"question": "Fish live in: (A) trees (B) water (C) sand", "answer": "B"},
{"question": "The sun rises in the: (A) west (B) south (C) east", "answer": "C"},
{"question": "Ice melts when: (A) heated (B) frozen (C) pressed", "answer": "A"},
]
MINI_INSTRUCTION: MiniBenchmark = [
{"question": "Respond with just the word 'ok'.", "answer": "ok"},
{"question": "Answer in one word: color of grass?", "answer": "green"},
{"question": "Answer yes or no: Is fire hot?", "answer": "yes"},
{"question": "Reply with the number three.", "answer": "3"},
{"question": "Say only: done", "answer": "done"},
]
MINI_BENCHMARKS: dict[str, MiniBenchmark] = {
"mini_mmlu": MINI_MMLU,
"mini_common_sense": MINI_COMMON_SENSE,
"mini_instruction": MINI_INSTRUCTION,
}
@dataclass
class ForgettingResult:
"""Outcome of a single forgetting eval."""
step: int
accuracy: float
baseline: float
delta: float
warning_level: Literal["green", "yellow", "red"]
class ForgettingDetector:
"""Run a mini benchmark periodically and report accuracy drops."""
def __init__(
self,
generate_fn: Callable[[str], str],
benchmark: str = "mini_mmlu",
threshold: float = 0.10,
) -> None:
if benchmark not in MINI_BENCHMARKS:
raise ValueError(
f"Unknown benchmark '{benchmark}'. "
f"Options: {', '.join(MINI_BENCHMARKS.keys())}"
)
self.generate_fn = generate_fn
self.benchmark_name = benchmark
self.benchmark = MINI_BENCHMARKS[benchmark]
self.threshold = threshold
self._baseline_accuracy: Optional[float] = None
def _evaluate(self) -> float:
correct = 0
for item in self.benchmark:
output = self.generate_fn(item["question"])
if not isinstance(output, str):
continue
if item["answer"].strip().lower() in output.strip().lower():
correct += 1
return correct / len(self.benchmark) if self.benchmark else 0.0
def run_baseline(self) -> float:
"""Compute the baseline accuracy before training starts."""
self._baseline_accuracy = self._evaluate()
return self._baseline_accuracy
def _build_result(self, step: int, accuracy: float) -> ForgettingResult:
baseline = self._baseline_accuracy if self._baseline_accuracy is not None else accuracy
delta = baseline - accuracy
if delta <= self.threshold:
level: Literal["green", "yellow", "red"] = "green"
elif delta <= self.threshold * 2:
level = "yellow"
else:
level = "red"
return ForgettingResult(
step=step,
accuracy=accuracy,
baseline=baseline,
delta=delta,
warning_level=level,
)
def check_forgetting(self, step: int) -> ForgettingResult:
"""Run the mini benchmark and compare against the baseline."""
if self._baseline_accuracy is None:
self.run_baseline()
current = self._evaluate()
return self._build_result(step=step, accuracy=current)