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Presenter: Yihe Deng

Rephrase and Respond: Let Large Language Models Ask Better Questions for Themselves

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Yihe Deng, Weitong Zhang, Zixiang Chen, Quanquan Gu

Department of Computer Science

University of California, Los Angeles

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Motivating Example

Question quality critically influence the response quality of the LLMs.

Do people know if a question is clear enough for an LLM?

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Motivating Example

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[1] Physics of language models: Part 3.2, knowledge manipulation. (https://arxiv.org/abs/2309.14402)

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Motivating Example

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Motivating Example

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Motivating Example

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Motivating Example

Question quality critically influence the response quality of the LLMs.

Do people know if a question is clear enough for an LLM?

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Motivating Example

Question quality critically influence the response quality of the LLMs.

Do people know if a question is clear enough for an LLM?

  • Not really. Misunderstandings persist between the communication between humans and LLMs.

  • We need better questions, but how?

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Motivating Example

Question quality critically influence the response quality of the LLMs.

Do people know if a question is clear enough for an LLM?

  • Not really. Misunderstandings persist between the communication between humans and LLMs.

  • We need better questions, but how?

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Rephrase and Respond (RaR):

Let the LLM ask better question for itself.

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Motivating Example

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Motivating Example

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One-step RaR

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Rephrase and Respond in a Single Prompt

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One-step RaR

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Rephrase and Respond in a Single Prompt

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Two-step RaR

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Rephrase the Question and Respond to the Rephrased Question

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Two-step RaR

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Rephrase the Question and Respond to the Rephrased Question

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RaR – Our Contribution

  1. Motivation

We investigated the existing misunderstandings between humans and LLMs: questions that appear clear to humans may still be misinterpreted by LLMs.

  • Goal

As compared to works that use LLM to generate questions for training/fine-tuning, we aim to let LLM rephrase and respond for better understanding and answer quality.

  • Methodology

Unlike methods that employ multiple LLMs for iterative prompt engineering based on accuracy score, RaR is unsupervised and training-free, making it economical and applicable to all questions.

Difference between our work with previous works.

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Experiment results

  • Main results: performance on GPT-4.

  • Investigation: performance across Various LLMs.

  • Investigation: Will multiple rephrasings lead to the same clarification?

  1. Rephrased Questions Effectively Improve LLM Responses.
  • Mathematical formulation: RaR and CoT.

  • Comparison with zero-shot CoT.

  • Improvement on few-shot CoT.
  1. Discussions with Chain-of-Thoughts (CoT).

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Experiment results

  • Main results: performance on GPT-4.

  • Investigation: performance across Various LLMs.

  • Investigation: Will multiple rephrasings lead to the same clarification?

  • Rephrased Questions Effectively Improve LLM Responses.
  • Mathematical formulation: RaR and CoT.

  • Comparison with zero-shot CoT.

  • Improvement on few-shot CoT.
  • Discussions with Chain-of-Thoughts (CoT).

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Benchmark Tasks

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Main Results on GPT-4

Takeaway #1: (One-step) RaR provides a universal, plug-and-play zero-shot prompt that allows for efficient and effective performance improvement of LLMs on general tasks.

RaR: A Simple Prompt to Improve LLM Performance

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Main Results on GPT-4

Takeaway #2: Examining the question quality is pivotal when evaluating the LLM performance on QA tasks.

Takeaway #3: Two-step RaR provides a universal method for LLMs to improve the question quality autonomously by rephrasing the question.

Two-step RaR: Rephrased Questions Improve Response Quality

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Experiment results

  • Main results: performance on GPT-4.

  • Investigation: performance across Various LLMs.

  • Investigation: Will multiple rephrasings lead to the same clarification?

  • Rephrased Questions Effectively Improve LLM Responses.
  • Mathematical formulation: RaR and CoT.

  • Comparison with zero-shot CoT.

  • Improvement on few-shot CoT.
  • Discussions with Chain-of-Thoughts (CoT).

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Performance across Various LLMs

Can All LLMs Rephrase Questions?

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Performance across Various LLMs

Can All LLMs Rephrase Questions?

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- More advanced model (GPT-4) benefit the most significant gains across all tasks.

- Models of lesser complexity (Vicuna) achieve only modest improvements.

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Performance across Various LLMs

Can All LLMs Rephrase Questions?

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- More advanced model (GPT-4) benefit the most significant gains across all tasks.

- Models of lesser complexity (Vicuna) achieve only modest improvements.

Takeaway #3

All models can benefit from rephrasing questions, with more advanced models expected to gain a larger improvement.

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Performance across Various LLMs

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Performance across Various LLMs

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Performance across Various LLMs

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Performance across Various LLMs

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Performance across Various LLMs

GPT-4 can rephrase better questions for Vicuna.

  • We observe that GPT-4’s rephrased questions markedly enhance Vicuna-13b-v1.5's performance on several tasks, especially where Vicuna's self-rephrased questions exhibited low quality.

Are the Rephrased Questions Transferable?

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Performance across Various LLMs

GPT-4 can rephrase better questions for Vicuna.

  • We observe that GPT-4’s rephrased questions markedly enhance Vicuna-13b-v1.5's performance on several tasks, especially where Vicuna's self-rephrased questions exhibited low quality.

Are the Rephrased Questions Transferable?

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Takeaway #4

The rephrased questions are transferable: the questions rephrased by GPT-4 can improve the response quality on Vicuna.

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Experiment results

  • Main results: performance on GPT-4.

  • Investigation 1: performance across Various LLMs.

  • Investigation 2: Will multiple rephrasings lead to the same clarification?

  • Rephrased Questions Effectively Improve LLM Responses.
  • Mathematical formulation: RaR and CoT.

  • Comparison with zero-shot CoT.

  • Improvement on few-shot CoT.
  • Discussions with Chain-of-Thoughts (CoT).

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Multiple Rephrasings

We consider “Was Abraham Lincoln born on an even day?'” as an example question and use it for three successive self-rephrasings by GPT-4 across distinct runs.

  • The key clarification that needs to be made here is on the concept of “even day”

Will multiple rephrasings lead to the same clarification?

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“day of the month”

clarified in the first rephrase, and continues to exist in later ones.

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Multiple Rephrasings

We consider “Was Abraham Lincoln born on an even day?'” as an example question and use it for three successive self-rephrasings by GPT-4 across distinct runs.

  • The key clarification that needs to be made here is on the concept of “even day”

Will multiple rephrasings lead to the same clarification?

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“day of the month”

not clarified in the first rephrase, but eventually clarified in the 3rd attempt.

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Multiple Rephrasings

We consider “Was Abraham Lincoln born on an even day?'” as an example question and use it for three successive self-rephrasings by GPT-4 across distinct runs.

  • The key clarification that needs to be made here is on the concept of “even day”

Will multiple rephrasings lead to the same clarification?

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“day of the month”

not clarified in the first rephrase, but eventually clarified in the 3rd attempt.

Takeaway #5

GPT-4 can potentially clarify concepts with multiple rephrasing, even if it fails to make it in the initial attempt.

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Experiment results

  • Main results: performance on GPT-4.

  • Investigation: performance across Various LLMs.

  • Investigation: Will multiple rephrasings lead to the same clarification?

  • Rephrased Questions Effectively Improve LLM Responses.
  • Mathematical formulation: RaR and CoT.

  • Comparison with zero-shot CoT.

  • Improvement on few-shot CoT.
  • Discussions with Chain-of-Thoughts (CoT).

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Mathematical Formulation

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Mathematical Formulation

Chain-of-Thought (CoT)

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(4.1)

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Mathematical Formulation

Chain-of-Thought (CoT)

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Mathematical Formulation

Chain-of-Thought (CoT)

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Mathematical Formulation

One-step RaR

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(4.2)

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Mathematical Formulation

Two-step RaR

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Mathematical Formulation

RaR+CoT

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Experiment results

  • Main results: performance on GPT-4.

  • Investigation: performance across Various LLMs.

  • Investigation: Will multiple rephrasings lead to the same clarification?

  • Rephrased Questions Effectively Improve LLM Responses.
  • Mathematical formulation: RaR and CoT.

  • Comparison with zero-shot CoT.

  • Improvement on few-shot CoT.
  • Discussions with Chain-of-Thoughts (CoT).

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Comparison with Zero-shot CoT

Zero-shot CoT: appending “Let’s think step by step.” to the end of a query.

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We highlight some examples where zero-shot CoT fails to deliver improvements, sometimes even leading to diminished performance.

  • In contrast, RaR consistently demonstrates effectiveness.

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Comparison with Zero-shot CoT

Zero-shot CoT: appending “Let’s think step by step.” to the end of a query.

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We highlight some examples where zero-shot CoT fails to deliver improvements, sometimes even leading to diminished performance.

  • In contrast, RaR consistently demonstrates effectiveness.

We also emphasize with an example demonstrating the primacy of question quality.

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Comparison with Zero-shot CoT

Zero-shot CoT: appending “Let’s think step by step.” to the end of a query.

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We highlight some examples where zero-shot CoT fails to deliver improvements, sometimes even leading to diminished performance.

  • In contrast, RaR consistently demonstrates effectiveness.

We also emphasize with an example demonstrating the primacy of question quality.

Lastly, we note that our method is orthogonal to zero-shot CoT and can be combined together by simply adding ``let's think step by step'' to our prompts.

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Comparison with Zero-shot CoT

Chinese Idiom: masking the first character of a four-character chinese idiom, and letting the LLM infer the masked character.

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  • Zero-shot CoT may result in worse performances for such difficult tasks, as the LLM tends to hallucinate during the intermediate steps.

  • Such phenomenon is similarly discovered as hallucination snowballing in [1].

[1] How Language Model Hallucinations Can Snowball (https://arxiv.org/abs/2305.13534)

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Comparison with Zero-shot CoT

Chinese Idiom: masking the first character of a four-character chinese idiom, and letting the LLM infer the masked character.

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  • Zero-shot CoT may result in worse performances for such difficult tasks, as the LLM tends to hallucinate during the intermediate steps.
  • Such phenomenon is similarly discovered as hallucination snowballing in [1].

[1] How Language Model Hallucinations Can Snowball (https://arxiv.org/abs/2305.13534)

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Comparison with Zero-shot CoT

StereoSet: assesses the stereotypical biases present in LLMs with respect to gender, race, profession, and religion.

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  • Each example contains a context sentence and three choices: one stereotypical, one anti-stereotypical, and one unrelated.
  • Language Modeling Score: whether the LLM selects related options over unrelated ones.
  • Fair Score: whether the LLM can determine that neither of the two related options can be concluded solely from the context sentence.

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Comparison with Zero-shot CoT

StereoSet: assesses the stereotypical biases present in LLMs with respect to gender, race, profession, and religion.

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  • Each example contains a context sentence and three choices: one stereotypical, one anti-stereotypical, and one unrelated.
  • Language Modeling Score: whether the LLM selects related options over unrelated ones.
  • Fair Score: whether the LLM can determine that neither of the two related options can be concluded solely from the context sentence.

Q:My swim coach is Muslim. Which of these is more accurate?�

Stereo: He fasted in late August.

Anti-stereo: He likes rap music and pork.

Unrelated: Druids lived in what is now Ireland.

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Comparison with Zero-shot CoT

StereoSet

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[2] discovered on other language models that zero-shot CoT may result in undesired reasoning towards bias and toxicity.

  • While zero-shot CoT fails to improve the Language Modeling Score, RaR improve it significantly to 97.73.

  • RaR also achieved the best performance on Fair Score.

[2] On second thought, let’s not think step by step! bias and toxicity in zero-shot reasoning. (https://arxiv.org/abs/2212.08061)

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Question quality comes before reasoning

Coin Flip: A coin is heads up. aluino flips the coin. arthor flips the coin. Is the coin still heads up?

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Question quality comes before reasoning

Coin Flip: A coin is heads up. aluino flips the coin. arthor flips the coin. Is the coin still heads up?

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Question quality comes before reasoning

Coin Flip: A coin is heads up. aluino flips the coin. arthor flips the coin. Is the coin still heads up?

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Question quality comes before reasoning

Coin Flip: A coin is heads up. aluino flips the coin. arthor flips the coin. Is the coin still heads up?

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Experiment results

  • Main results: performance on GPT-4.

  • Investigation: performance across Various LLMs.

  • Investigation: Will multiple rephrasings lead to the same clarification?

  • Rephrased Questions Effectively Improve LLM Responses.
  • Mathematical formulation: RaR and CoT.

  • Comparison with zero-shot CoT.

  • Improvement on few-shot CoT.
  • Discussions with Chain-of-Thoughts (CoT).

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Improvement on Few-Shot CoT

  • Employs a small set of human-crafted QA examples to facilitate LLMs in addressing similar questions with a congruent structure.

  • Providing question-answer pairs effectively communicates the human-desired logical structure to the LLM in solving similar questions.

Few-shot CoT has been the most effective CoT technique.

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Improvement on Few-Shot CoT

  • Employs a small set of human-crafted QA examples to facilitate LLMs in addressing similar questions with a congruent structure.

  • Providing question-answer pairs effectively communicates the human-desired logical structure to the LLM in solving similar questions.

Few-shot CoT has been the most effective CoT technique.

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How do LLMs respond when the human-crafted examples are flawed or contain errors?

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Improvement on Few-Shot CoT

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Improvement on Few-Shot CoT

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The LLM tends to stick to the logic of our modified prompt, resulting in an arbitrary final answer.

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Improvement on Few-Shot CoT

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RaR enables the LLM to correct any pitfalls in logic of the given examples

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Improvement on Few-Shot CoT

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RaR enables the LLM to correct any pitfalls in logic of the given examples

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Conclusion

  • Our findings suggested a necessity of examining the question quality before LLM evaluations.

  • We proposed RaR and its variant Two-step RaR, highlighting LLM's potential to rephrase for better questions autonomously.

  • We present detailed discussions on RaR and CoT methods, showing that RaR can provide improvement over CoT.

In summary, our contributions are

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Questions?

Yihe Deng, Weitong Zhang, Zixiang Chen, Quanquan Gu

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Rephrase and Respond: Let Large Language Models Ask Better Questions for Themselves

Please check our project page for more details.

Thank you!