Measuring pseudo relevance feedback & CLIR

In this poster, we report on the effects of pseudo relevance feedback (PRF) for a cross language image retrieval task using a test collection. Typically PRF has been shown to improve retrieval performance in previous CLIR experiments based on average precision at a fixed rank. However our experiments have shown that queries in which no relevant documents are returned also increases. Because query reformulation for cross language is likely to be harder than with monolingual searching, a great deal of user dissatisfaction would be associated with this scenario. We propose that an additional effectiveness measure based on failed queries may better reflect user satisfaction than average precision alone.