  The 1st edition of the workshop on Mixed-Initiative ConveRsatiOnal Systems
(MICROS@ECIR2021) aims at investigating and collecting novel ideas and
contributions in the field of conversational systems. Oftentimes, the users
fulfill their information need using smartphones and home assistants. This has
revolutionized the way users access online information, thus posing new
challenges compared to traditional search and recommendation. The first edition
of MICROS will have a particular focus on mixed-initiative conversational
systems. Indeed, conversational systems need to be proactive, proposing not
only answers but also possible interpretations for ambiguous or vague requests.
