. This paper describes a number of experiments that explored the issues surrounding the retrieval of spoken documents. Two such issues were examined. First, attempting to find the best use of speech recogniser output to produce the highest retrieval effectiveness. Second, investigating the potential problems of retrieving from a so-called "mixed collection ", i.e. one that contains documents from both a speech recognition system (producing many errors) and from hand transcription (producing presumably near perfect documents). The result of the first part of the work found that merging the transcripts of multiple recognisers showed most promise. The investigation in the second part showed how the term weighting scheme used in a retrieval system was important in determining whether the system was affected detrimentally when retrieving from a mixed collection. 1 Introduction Over the past few years the field of Information Retrieval (IR) has directed increasing interest towards the retri...

Often, information retrieval from various other media is analogous to text-based retrieval; however, accessing documents in e.g. audio or video formats causes some extra problems, in particular with respect to document segmentation, choice of indexing features, and robustness. We review these difficulties, together with some previous attempts to overcome them, and then describe a very flexible, modular IR system which has been designed with a specific eye towards these issues.