The document summarizes three models of consumer decision making:
1. The Howard-Sheth model describes three levels of decision making - extensive problem solving when a consumer has no information, limited problem solving when a consumer has some knowledge, and habitual response behavior when a consumer is familiar with options.
2. The Nicosia model focuses on the relationship between firms and consumers, with firms communicating messages and consumers responding through purchase. It outlines four fields - consumer attitudes, search/evaluation, purchase act, and feedback.
3. The Engel-Blackwell-Kollat model describes five decision process stages, how consumers receive information, and individual/environmental influences on the process.