Summary
The paper introduces a new prompting method, Self-Discover, that enhances the complex reasoning abilities of Large Language Models. Self-Discover consists of two stages. At the first one, the method develops a task-adapted prompt by performing 3 steps: SELECT, when the LLM selects the reasoning modules (RMs) from a pre-defined list, ADAPT, when the model adapts the chosen reasoning modules to the task, and IMPLEMENT, when the model, conditioned on the adapted reasoning modules, generates the reasoning structure as a JSON. Each step is performed in a zero-shot manner and controlled by a dedicated meta-prompt. The resulting reasoning structure is used in the final second stage, as part of the prompt to solve each task and produce the output. For each task instance, the LLM first reasons by completing the JSON value fields, and then outputs the answer. Self-Discover is compared to several baselines: Direct Prompting, CoT (+Self-Consistency), Plan-and-Solve, Majority voting of RMs, and Best of each RM, as well as Graph-of-Thought (GoT) and Tree-of-Thought (ToT). Evaluation is performed on BIG-Bench Hard (BBH), Thinking for Doing (T4D), and (subsampled) MATH benchmarks. The results demonstrate the superiority of Self-Discover against the baselines above in terms of performance while maintaining comparatively low computational cost, expressed in the number of necessary inference calls. The ablation study highlights that each step of Stage 1 significantly contributes to the overall performance. The generated reasoning structures appear to be general and transferable between different LLMs, compared to Optimized Prompts (OPRO).
Strengths
- The paper proposes a simple yet effective approach that greatly improves the reasoning abilities of LLMs. This is especially emphasized by the low computational costs of the method of only 3 extra inference calls per task. The method unifies multiple prompting-reasoning techniques and thus is scalable and adaptable.
- The evaluations are purposeful, and every major claim of the paper is supported by empirical evidence, including all the necessary ablation studies justifying the steps of Stage 1. A thorough analysis of the methods' performance, showing tasks where the method excels more, is included in the paper.
Weaknesses
- The paper doesn't emphasize enough that the method requires task adaptation. This is a crucial detail, as, unlike CoT or ToT, Self-Discover cannot be deployed as a general zero-shot agent, but requires some specialized prompting with task examples. This limitation is addressed barely in the paper. Though this is not a huge disadvantage, it places the method right between zero-shot methods (CoT / ToT / GoT / PS) and task-adaptive methods (OPRO / DSPy). Thus, more comparisons with the prompt adaptation techniques should be present in the paper, and the efficiency of Self-Discover should be emphasized when comparing to them.
- The authors claim that their method "composes atomic reasoning models into a reasoning structure", but this seems misleading. Figure 4 demonstrates that the method only slightly outperforms the best RM baseline, suggesting that no actual "composition" is happening, but only a selection and adaptation of the best fitting reasoning technique. This requires further investigation, for example, by analyzing which reasoning modules were picked for a task, and ablating the performance on these modules. This would reveal whether the model indeed uses multiple reasoning modules or only one in its prediction.
Questions
- How robust is the method to changes in the list of reasoning modules? An ablation study on them, or at least the list of chosen modules for each task would reveal this information. Also, how robust is the method to the set of chosen task examples? What was their number in the experiments, and does varying their number or themselves affect the performance?
- What were the parameters of ToT & GoT in the experiments? The value of the breadth parameter can largely affect the performance of these methods.
- What modifications can be applied to the set of RM to increase the performance on the algorithmic tasks? I assume some specialized algorithmic prompting can be useful. What you also include the relationship between reasoning modules and the tasks in which they are useful, and assert that the model chooses the correct reasoning module?
Limitations
As mentioned above, though the method is very effective, it is dependent on the set of chosen task examples, and so is task-adaptable, and not completely zero-shot. This limitation is not emphasized enough in the paper.
However, overall, it is a nice paper with promising results, which once again underscores the power of optimal prompting and alignment.