🤖 AI Summary
This work addresses the accuracy-efficiency trade-off in language model sequence generation caused by fixed inference step budgets. Methodologically, it introduces learnable `<pause>` and `<don’t know>` tokens, framing decoding as a sequential decision process with explicit time cost, and proposes the CYB family of loss functions—including CYB-VA (a variational approximation) and CYB-DP (a computational budget penalty)—to enable fine-grained, context-aware adaptive pausing and resuming. Key contributions include: (i) the first end-to-end framework enabling language models to autonomously control inference latency; (ii) achieving baseline performance with only one-third of the training data; and (iii) significantly improving accuracy on complex tokens while exhibiting sensitive, adaptive behavior toward syntactic ambiguity and morphological structure.
📝 Abstract
We explore a class of supervised training objectives that allow a language model to dynamically and autonomously scale the number of compute steps used for each input token. For any token, the model can request additional compute steps by emitting a <don't know> output. If the model is granted a delay, a specialized <pause> token is inserted at the next input step, providing the model with additional compute resources to generate an output. The model can request multiple pauses. To train the model to use <don't know> outputs judiciously and to calibrate its uncertainty, we frame the selection of each output token as a sequential-decision problem with a time cost. We refer to the class of methods as $ extit{Catch Your Breath}$ losses and we study three methods in this class: CYB-AP frames the model's task as anytime prediction, where an output may be required at any step and accuracy is discounted over time; CYB-VA is a variational approach that aims to maximize prediction accuracy subject to a specified distribution over stopping times; and CYB-DP imposes a penalty based on a computational budget. Through fine-tuning experiments, we identify the best performing loss variant. The CYB model needs only one third as much training data as the baseline (no pause) model needs to achieve the same performance, and half as much data as a model with pauses and a cross-entropy loss. We find that the CYB model requests additional steps when doing so improves accuracy, and the model adapts its processing time to token-level complexity and context. For example, it often pauses after plural nouns like $ extit{patients}$ and $ extit{challenges}$ but never pauses after the first token of contracted words like $ extit{wasn}$ and $ extit{didn}$, and it shows high variability for ambiguous tokens like $ extit{won}$, which could function as either a verb or part of a contraction.