In the taxonomy of learning domains developed by Howard Bloom, the cognitive domain is one of three areas of development, the other two being affective and psychomotor. The cognitive domain is based on the acquisition of knowledge and intellectual skills, and can be assessed in a variety of ways. Bloom developed an additional hierarchy of cognitive skills that comprise this domain, each of which represents a higher order of thinking that one can display.
On the bottom of the cognitive domain is remembering; this requires the learner to simply recall facts or information. When a student remembers dates from World War II, they are functioning at this basic level. The second element of this hierarchy is understanding; this requires the student to comprehend the concepts being presented. When students can grasp why America retaliated against Japan for the attack on Pearl Harbor, they have reached this second level. The third level of the hierarchy is application; here, they must take the concepts they have learned and relate them to other concepts. Seeing parallels between the internment of Japanese-Americans during World War II and the increasing presence of Islamophobia in today's society is an example of cognitive functioning at this level.
The next level, analysis, requires the student to think critically about some element being learned. By breaking down the military strategies employed during D-Day, students are able to analyze why the invasion was successful. The second level from the top, evaluation, requires the students to make a judgment. When students consider whether or not dropping the atomic bomb on Hiroshima and Nagasaki was the correct course of action, they are thinking at this level of cognitive processing. Finally, the final level of Bloom's taxonomy of the cognitive domain is creation. When students take all the information they have learned about World War II and write a first-person narrative of a person involved in the conflict in some way, they are developing their thoughts and analysis in such a way that allows them to add to existing knowledge. At this level, they are functioning at the highest order of thinking and have succeeded in mastery of the cognitive domain.