  Generating value from data requires the ability to find, access and make
sense of datasets. There are many efforts underway to encourage data sharing
and reuse, from scientific publishers asking authors to submit data alongside
manuscripts to data marketplaces, open data portals and data communities.
Google recently beta released a search service for datasets, which allows users
to discover data stored in various online repositories via keyword queries.
These developments foreshadow an emerging research field around dataset search
or retrieval that broadly encompasses frameworks, methods and tools that help
match a user data need against a collection of datasets. Here, we survey the
state of the art of research and commercial systems in dataset retrieval. We
identify what makes dataset search a research field in its own right, with
unique challenges and methods and highlight open problems. We look at
approaches and implementations from related areas dataset search is drawing
upon, including information retrieval, databases, entity-centric and tabular
search in order to identify possible paths to resolve these open problems as
well as immediate next steps that will take the field forward.
