This is the accepted version of the paper.This version of the publication may differ from the final published version. **Vocab: "data" is plural. So, need "data are" instead of "data is". **Vocab: It's a Why-oriented approach (capitalized) **Vocab: It's naïve Bayes (lower-case 'n') **Vocab/numbering: change the following globally:
Permanent repository linkPrinciple (iv) -> Principle ML-2 **Length: TiiS suggests manuscripts be between 10,000 and 15,000 words. Machine learning techniques are increasingly used in intelligent assistants, software targeted at and continuously adapting to assisting end users with email, shopping, and other tasks. Examples include desktop SPAM filters, recommender systems, and handwriting recognition. Fixing such intelligent assistants when they learn incorrect behavior, however, has received only limited attention. To directly support end-user "debugging" of assistant behaviors learned via statistical machine learning, we present a Why-oriented approach that allows users to ask questions about how the assistant made its predictions, provides answers to these "why" questions, and allows users to interactively change these answers to "debug" these assistants' current and future predictions. To understand the strengths and weaknesses of the approach, we conducted an exploratory study to investigate barriers that participants would encounter when debugging an intelligent assistant using our approach, and the information those participants requested to overcome these barriers. To help ensure the inclusiveness of our investigation, we also explored how gender differences played a role in barriers and information needs. We then use these results to consider opportunities for Why-oriented approaches to address the users' barriers and information needs.