  This paper introduces the Ninth Dialog System Technology Challenge (DSTC-9).
This edition of the DSTC focuses on applying end-to-end dialog technologies for
four distinct tasks in dialog systems, namely, 1. Task-oriented dialog Modeling
with unstructured knowledge access, 2. Multi-domain task-oriented dialog, 3.
Interactive evaluation of dialog, and 4. Situated interactive multi-modal
dialog. This paper describes the task definition, provided datasets, baselines
and evaluation set-up for each track. We also summarize the results of the
submitted systems to highlight the overall trends of the state-of-the-art
technologies for the tasks.
