Consider the universal set, U, to be the set of all products and brands which will satisfy a given need. The awareness or knowledge set, A, is defined as all of the products and brands within the universal set that the consumer is aware of. This awareness can be derived from a product search, brand familiarity, advertisements, word-of-mouth, or any other method which informs the consumer of a viable option. While the awareness set is largely composed of products that reside in the consumer's long-term memory, the awareness set can also be expanded by products found during the search process – such as recommended products on an e-commerce site or shelves in a supermarket. Thus A \subseteq U.
