On the Effectiveness of Contextualisation Techniques in Spoken Query Spoken Content Retrieval

In passage and XML retrieval, contextualisation techniques seek to improve the rank of a relevant element by considering information from its surrounding elements and its container document. Recent research has demonstrated that some of these techniques are also particularly effective in spoken content retrieval tasks (SCR). However, no previous research has directly compared contextualisation techniques in an SCR setting, nor has it studied their potential to provide robustness to speech recognition errors. In this paper, we evaluate different contextualisation techniques, including a recently proposed technique based on positional language models (PLM) on the task of retrieving relevant spoken passages in response to a spoken query. We study the bene fits of these techniques when queries and documents are transcribed with increasingly higher error rates. Experimental results over the Japanese NTCIR SpokenQuery&Doc collection show that combining global and local context is beneficial for SCR and that models usually benefit from using larger amounts of context in highly noisy conditions.