Unlocking Conversational Search: Leveraging Large Language Models for Reusable Test Collections

Thursday 10 April 2025


Conversational search has become an essential part of our daily lives, allowing us to easily retrieve information and answer questions using natural language queries. However, creating test collections for evaluating conversational search systems is a challenging task due to the dynamic nature of conversations.


Researchers have traditionally used pooling strategies to create these test collections, where they select the top-ranked documents from each contributing system. While this approach is efficient, it has its limitations. For example, it can lead to biases in evaluation results and make it difficult to compare systems that did not contribute to the pool.


Recently, a team of researchers proposed an innovative solution to address these issues. They used large language models (LLMs) to fill holes in test collections by leveraging existing judgments. This approach has the potential to improve the reusability of test collections and provide more accurate evaluation results.


The research focused on two conversational search test collections, TREC iKAT 23 and TREC CAsT 22, which are well-known benchmarks for evaluating conversational search systems. These collections feature complex queries with multiple turns and varied responses, making them ideal for testing the proposed approach.


The researchers first analyzed the characteristics of these test collections and identified areas where LLMs could be used to fill holes. They then trained an LLM model on a dataset of existing judgments from previous evaluations and used it to predict relevance scores for unjudged documents.


The results showed that the LLM-based approach significantly improved the reusability of test collections, allowing for more accurate evaluation results and better system comparisons. The researchers also found that fine-tuning the LLM model using few-shot prompting resulted in high agreement with human assessors, indicating its potential for real-world applications.


One of the key advantages of this approach is its ability to adapt to changing conversational contexts. Unlike traditional pooling strategies, which rely on fixed relevance judgments, the LLM-based method can learn from existing judgments and generate new ones based on the context of the conversation.


The implications of this research are far-reaching, with potential applications in various fields such as customer service chatbots, voice assistants, and search engines. By enabling more accurate evaluation results and better system comparisons, this approach could lead to significant improvements in conversational search technology.


In summary, researchers have developed a novel method for filling holes in conversational search test collections using large language models.


Cite this article: “Unlocking Conversational Search: Leveraging Large Language Models for Reusable Test Collections”, The Science Archive, 2025.


Conversational Search, Test Collections, Pooling Strategies, Language Models, Evaluation Results, System Comparisons, Customer Service, Voice Assistants, Search Engines, Large Language Models


Reference: Zahra Abbasiantaeb, Chuan Meng, Leif Azzopardi, Mohammad Aliannejadi, “Improving the Reusability of Conversational Search Test Collections” (2025).


Leave a Reply