t1-structured-reasoning-full-kimi-k2-instruct-0905

Structured reasoning evaluation: instead of injecting synthesized facts, this uses a static system prompt that teaches the model a heuristic search FORMAT with explicit structural markers ([STEP], [PRUNE], [BACKTRACK], [REVIEW OPTIONS], [SOLUTION FOUND]).

Inspired by HandCraftedCountdownSearch — models SFT'd on structured search traces significantly outperform free-form CoT. This tests whether prompt-time format instruction alone can capture some of that benefit.

Performance Comparison

Metric	Base	Structured	Delta
pass@1	0.9000 (90.0%)	0.3000 (30.0%)	-0.6000 (-60.0%)

Experimental Details

Parameter	Value
Inference model	together_ai/moonshotai/Kimi-K2-Instruct-0905
Prompt style	full
Temperature	0.7
Top-p	0.95
Max tokens	65536
Samples per problem	1
Enable thinking	True
Total problems	10
Base eval source	t1-base-eval-together_ai-qwen-qwen3-235b-a22b-thinkin-12arg

System Prompt Used (full style)

You are solving a countdown arithmetic problem. You must find an expression using the given numbers (each exactly once) that equals the target.

REASON USING STRUCTURED HEURISTIC SEARCH. Do not just guess — systematically search for the answer using the format below. This is critical: use the exact markers shown to organize your reasoning.

=== REASONING FORMAT ===

Use these markers to structure every step of your thinking:

[STEP N: COMBINE] — Try combining two numbers with an operation. Show: a OP b = result. State remaining numbers and how far from target.

[PRUNE] — BEFORE trying an operation, check if it's useful. Skip it if:
  - Division doesn't produce an integer
  - The result moves AWAY from target (current < target? don't subtract/divide. current > target? don't add/multiply)
  Say what you're skipping and why.

[BACKTRACK] — Current path is stuck or getting worse. State why (too high? too low? no numbers left?) and go back to try a different combination.

[REVIEW OPTIONS] — When stuck, list ALL remaining possible combinations, score each by |result - target|, and pick the best one to try next.

[SOLUTION FOUND] — You hit the target! Verify: recompute the expression, confirm each number is used exactly once, then give the answer.

=== KEY HEURISTIC ===

DIRECTIONAL SEARCH: At every step, check if your current value is above or below the target.
  - Below target → only try + and * (go UP)
  - Above target → only try - and / (go DOWN)
This cuts your search space in half and prevents wasted exploration.

=== WORKED EXAMPLE ===

Target: 23, Numbers: [4, 7, 3]

[STEP 1: COMBINE]
Let me scan first moves. Best candidates by closeness to 23:
  4 * 7 = 28 (distance 5) ← closest
  4 + 7 = 11 (distance 12)
  7 * 3 = 21 (distance 2) ← very close!
  7 + 3 = 10 (distance 13)
Try: 7 * 3 = 21. Remaining: [4]. Current: 21, need 23.

[STEP 2: COMBINE]
Current 21 < target 23, so only try + and *.
21 + 4 = 25 (distance 2)
21 * 4 = 84 (distance 61)
[PRUNE] 21 * 4 = 84 — way t...

Dataset Info

• Rows: Structured reasoning evaluation results (one row per problem)
• Columns: question, metadata, task_source, formatted_prompt, response, eval_correct, and associated metadata

Usage

from datasets import load_dataset

dataset = load_dataset("reasoning-degeneration-dev/t1-structured-reasoning-full-kimi-k2-instruct-0905", split="train")
print(f"Loaded {len(dataset)} rows")

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This dataset is tracked in reasoning-degeneration-dev/PROJECT-MANIFEST