Experiences Collecting Genuine Spoken Enquiries using WOZ Techniques

Experiences Collecting Genuine Spoken Enquiries using WOZ Techniques Roger Moore and Angela Morris Speech Research Unit Defence Research Agency Malvern (RSRE) St. Andrews Road, Malvern, Worcs., WR14 3PS, United Kingdom ABSTRACT 3. THE WIZARD This paper presents SRU's first experiences collecting un- scripted speech data using the 'Wizard of Oz' technique to provide a genuine telephone-based route planning service. Although only a limited quantity of data has been collected so far, several valuable insights into the nature of future speech- based human-machine interaction have been obtained. 1. INTRODUCTION Many laboratories have now used the so-called 'Wizard of Oz' (WOZ) technique for eliciting spontaneous spoken human-machine dialogue in order (i) to study the result- ing speech and (ii) to evaluate the necessary speech tech- nology and natural language processing systems [1]. The technique is particularly valuable because it enables user behaviour to be studied under conditions which are not constrained by the limitations of current technological (or theoretical) capabilities. However, many such exercises involve 'volunteer' users whose behaviour is prescribed by a pre-prepared sce- nario [6] thereby removing one potentially crucial aspect of human-machine interaction, namely any behavioural events which are unique to genuine (i.e. motivated) and un-preprepared transactions [4]. This paper presents $RU's first experiences collecting unscripted speech data using the WOZ technique by the provision of a genuine voice-based telephone enquiry ser- vice to personnel on the RSRE site. 2. THE TASK DOMAIN The enquiry service was configured around a commer- cially available route planning software package. The package runs on a PC and contains map and gazetteer information covering the majority of the United King- dom. Its main feature is its ability to find the shortest and/or quickest routes between two locations in accor- dance with a range of specifyable variables such as pref- erences for certain classes of roads and driving speeds. Alternative routes can also be found. Clearly the behaviour of the wizard will very much influ- ence the nature of the resulting corpus, and constraints (such as restricting the vocabulary) can be placed on a wizard in a variety of ways [2]. However, in order not to restrict or influence callers' be- haviour, it was decided that very few restrictions should be placed on the wizard apart from the use of a stock opening phrase and the provision of a few standard reply templates simply in order to reduce the wizard's work load. In general, the design for the wizard's behaviour was based on information derived from the procedures em- ployed by a commercial company who already provide a route planning service over the telephone (in this case the enquiries being made by tone dialling) based on the same software package. Every attempt was made to remove all distinctly hu- man characteristics from the wizard's speech such as false starts and stutters, and great care was taken to ensure that breath noise and key clicks were not audible to the caller. 4. THE EXPERIMENTAL CONFIGURATION As well as implementing a genuine telephone-based en- quiry service …

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