1. The HIGGINS domain The primary domain of HIGGINS is city navigation for pedestrians. Secondarily, HIGGINS is intended to provide simple information about the immediate surroundings. This is a 3D test environment

2. HIGGINS research issues Which factors should govern the dialogue strategy regarding feedback and information detail? –user experience, success, errors, initiative... How do different levels of feedback and detail in system responses affect robustness and efficiency of the dialogue? How to find and categorise errors –e.g. confidence measures in different system modules How should the system act when it doesn't or only partially understands –clarification or "wait and see" How does the user's beliefs about the system’s understanding correlate to its actual understanding, depending on error handling strategy?

3. Error handling what should the system do when it understands nothing or just a fragment of the user’s utterance? (non- understanding) traditional method – signal non-understanding – encourage the user to repeat “I didn’t understand” “I didn’t hear what you said” – leads to hyperarticulation the user just repeats

4. Human handling of non- understanding Experiment with humans Task: navigate in a simulated campus Vocoder User Operator Listens Speaks Reads Speaks ASR

5. Results Humans do not often signal non- understanding (30% of the time). Instead, they ask questions such as “can you see a red building?”, confirming a hypothesis about the situation but not about what has been said. This leads to faster –error recovery –greater experience of task success Skantze, "Exploring human error handling strategies: implications for spoken dialogue systems", 2003