ReAct¹ (Reason + Act) is a paradigm that enables language models to solve complex tasks through natural language reasoning and actions. It allows an LLM to perform certain actions, such as retrieving external information, and then reason based on the retrieved data.

ReAct systems extend MRKL systems by adding the ability to reason about the actions they can perform.

Example

Below is an example from HotPotQA², a question-answering dataset requiring complex reasoning. ReAct allows the LLM to reason about the question (Thought 1), take actions (e.g., querying Google) (Act 1). It then receives an observation (Obs 1) and continues the thought-action loop until reaching a conclusion (Act 3).

ReAct System (Yao et al.)

Readers with knowledge of reinforcement learning may recognize this process as similar to the classic RL loop of state, action, reward, state,... ReAct provides some formalization for this in their paper.

Results

Google experimented with the PaLM LLM³ using ReAct, and the results showed promising improvements in complex reasoning tasks. ReAct was tested on datasets such as FEVER⁴, focusing on fact extraction and verification.

ReAct Results (Yao et al.)

Footnotes

Yao, S., Zhao, J., Yu, D., Du, N., Shafran, I., Narasimhan, K., & Cao, Y. (2022). ↩
Yang, Z., Qi, P., Zhang, S., Bengio, Y., Cohen, W. W., Salakhutdinov, R., & Manning, C. D. (2018). HotpotQA: A Dataset for Diverse, Explainable Multi-hop Question Answering. ↩
Chowdhery, A., Narang, S., Devlin, J., Bosma, M., Mishra, G., Roberts, A., Barham, P., Chung, H. W., Sutton, C., Gehrmann, S., Schuh, P., Shi, K., Tsvyashchenko, S., Maynez, J., Rao, A., Barnes, P., Tay, Y., Shazeer, N., Prabhakaran, V., … Fiedel, N. (2022). PaLM: Scaling Language Modeling with Pathways. ↩
Thorne, J., Vlachos, A., Christodoulopoulos, C., & Mittal, A. (2018). FEVER: a large-scale dataset for Fact Extraction and VERification. ↩

Edit this page

Word count: 0

Get AI Certified by Learn Prompting

Need Business GenAI Training?

Contact Sales

Want to keep learning

Course Catalog

Want to test your knowledge

Certification Exam

Questions?