  Retrieving paragraphs to populate a Wikipedia article is a challenging task.
The new TREC Complex Answer Retrieval (TREC CAR) track introduces a
comprehensive dataset that targets this retrieval scenario. We present early
results from a variety of approaches -- from standard information retrieval
methods (e.g., tf-idf) to complex systems that using query expansion using
knowledge bases and deep neural networks. The goal is to offer future
participants of this track an overview of some promising approaches to tackle
this problem.
