Census method refers to the complete enumeration of a universe. A universe may be a place, a group of people or a specific locality through which we collect the data. Census method is necessary in some cases like population census, Agriculture Census, animal census etc for gaining vast knowledge.
Educational psychology is the branch of psychology, so educational psychology uses all those methods for data collection which are used in general psychology to get the maximum data and information about various human behaviors in order to arrive on conclusion. The following are the main data collection method