A stimulus is a unit of input from either an external or internal source that can affect sight, smell, taste, touch, or hearing. 3. When Alan buys rock-climbing equipment, he will only buy Black Diamond, Betzl, Edelweiss, or Wild Country brands even though other brands exist. These listed brands make up Alan's awareness set. This is Alan's evoked set. 4. Once an individual's evoked set has been established, evaluation of those alternatives will determine what information must be obtained during the information search. The information search stage usually yields an evoked set and precedes evaluation of alternatives. 5. There arc several tools marketing managers can use to increase cognitive dissonance, which enhances consumers' attitude toward their brand.