  Information access needs to be uncomplicated, users rather use incorrect data
which is easily received than correct information which is harder to obtain.
Querying bibliographic metadata from digital libraries mainly supports simple
textual queries. A user's demand for answering more sophisticated queries could
be fulfilled by the usage of SQL. As such means are highly complex and
challenging even for trained programmers, a domain-specific query language is
needed to provide a straightforward way to access data.
  In this paper we present SchenQL, a simple query language focused on
bibliographic metadata in the area of computer science while using the
vocabulary of domain-experts. By facilitating a plain syntax and fundamental
aggregate functions, we propose an easy-to-learn domain-specific query language
capable of search and exploration. It is suitable for domain-experts as well as
casual users while still providing the possibility to answer complicated
queries. A user study with computer scientists directly compared our query
language to SQL and clearly demonstrated SchenQL's suitability and usefulness
for given queries as well as users' acceptance.
