Open domain question answering has become a very active research area over the past few years, due in large measure to the stimulus of the TREC Question Answering track. This track addresses the task of finding answers to natural language (NL) questions (e.g. "How tall is the Eiffel Tower?" "Who is Aaron Copland?") from large text collections. This task stands in contrast to the more conventional IR task of retrieving documents relevant to a query, where the query may be simply a collection of keywords (e.g. ``Eiffel Tower", ``American composer, born Brooklyn NY 1900, ...'').
The IR4QA workshops aim to foster research on the specific challenges of using IR techniques within QA systems.