%0 Conference Proceedings %A McGuinness, D.L., Glass, A., Wolverton, M., and Pinheiro da Silva, P. %T A Categorization of Explanation Questions for Task Processing Systems %B Proceedings of the 2007 Workshop on Explanation-aware Computing (ExaCt-2007) %C Vancouver, Canada %D 2007 %X A critical aspect of any explanation module is the set of user questions the system will be able to address. However, there has been relatively little work on listing and organizing the various categories of questions helpful to explanation. In this paper we address this problem by proposing a categorization of question types relevant to explaining task processing. For each question type, we also propose alternative explanation strategies for answering them. This categorization has helped to drive our work on an integrated cognitive explanation environment that has been used to explain the behavior of CALO, a software cognitive assistant that learns and organizes.