Coinciding with the elections that take place in Spain, the CIS carries out pre- and post-electoral studies in order to conduct research into the characteristics of citizens' voting behaviour.
The CIS passes the data collected in pre-election surveys through an estimation model. They are presented jointly with the results preview of said surveys. Use of other models might give rise to different election estimations. Access free of charge to the data matrices enables each user to apply his own estimation model.