Conversational Recommendation as Retrieval: A Simple, Strong Baseline
This addresses the scalability issues in CRS by reducing reliance on external knowledge, though it is incremental as it builds on existing IR methods.
The paper tackles the problem of conversational recommendation systems (CRS) by proposing an information retrieval (IR)-styled approach that treats conversations as queries and items as documents, showing it compares favorably with more complex baselines on a popular benchmark.
Conversational recommendation systems (CRS) aim to recommend suitable items to users through natural language conversation. However, most CRS approaches do not effectively utilize the signal provided by these conversations. They rely heavily on explicit external knowledge e.g., knowledge graphs to augment the models' understanding of the items and attributes, which is quite hard to scale. To alleviate this, we propose an alternative information retrieval (IR)-styled approach to the CRS item recommendation task, where we represent conversations as queries and items as documents to be retrieved. We expand the document representation used for retrieval with conversations from the training set. With a simple BM25-based retriever, we show that our task formulation compares favorably with much more complex baselines using complex external knowledge on a popular CRS benchmark. We demonstrate further improvements using user-centric modeling and data augmentation to counter the cold start problem for CRSs.