BRIDGE: Budget-aware Reasoning via Intermediate Distillation with Guided Examples

TL;DR

BRIDGE is a two-phase, budget-aware distillation framework that effectively transfers knowledge from large models to tiny models by using intermediate teachers and synthetic rationales, improving performance with fewer resources.

Contribution

Introduces BRIDGE, a novel two-phase distillation method that leverages a mid-sized teacher assistant and synthetic data to efficiently transfer reasoning capabilities under budget constraints.

Findings

Achieves 28-41% performance gains on benchmarks.

Reduces teacher query costs by 10x while maintaining high accuracy.

Surpasses direct distillation baselines with fewer resources.

Abstract

Distilling knowledge from large proprietary models (e.g., GPT-4) to tiny deployable models (less than 1B parameters) faces a critical capacity-budget trap: the 1000x capacity gap between teachers and students prevents effective direct transfer, while API costs prohibit extensive data collection. We introduce BRIDGE (Budget-Aware Reasoning via Intermediate Distillation), a two-phase framework that resolves these constraints through strategic intermediation and budget asymmetry. In Phase 1, a mid-sized Teacher Assistant (TA; e.g., about 7B) learns from the black-box teacher on a strictly limited subset of data (e.g., 3-5%), selected via a zero-API-cost pipeline that balances entropic difficulty and semantic diversity using only local TA inference. In Phase 2, we exploit this asymmetry-teacher queries are expensive, whereas TA inference is free to amplify supervision: the refined TA generates synthetic rationales for the full dataset to train the tiny student. Crucially, we apply an instruction-tuning curriculum to establish behavioral alignment in the tiny student before transferring reasoning. Our theoretical analysis shows that BRIDGE yields tighter generalization bounds than direct distillation when data is abundant. Experiments across medical, legal, and financial benchmarks demonstrate consistent improvements: BRIDGE delivers student performance gains of 28-41%, closing the capability gap with proprietary teachers by 12-16% while using 10x fewer teacher queries. Notably, BRIDGE defies the conventional cost-performance frontier, surpassing direct distillation baselines that use 100% of the budget while consuming only 5% of the resources.