Principles of Persuasion (Weapons of Influence)
1. Reciprocity
Users are more likely to comply with a request if they feel obligated because something has been given to them already3.
2. Commitment and Consistency
Users are more likely to act in a way that is consistent with some act they’ve already taken. Importantly, this occurs even if the user might not have performed the second act without performing the first act. That is consistency is a strong reason for the user to act and once committed to a course of action they are more likely to stay on it3.
3. Social Proof
Users are more likely to perform some act if they know other users have performed the same act especially when they are not sure whether they should. For example, if a person is buying a piece of jewelry, but isn’t sure if it’s good because they don’t know how to value jewelry, they are more likely to buy it if they know other persons bought it (for a similar price)3.
4. Liking
Users are more likely to perform some act if other users that they like have performed the same act. This principle is exploited, for example, by facebook ads that show friends who have liked that advertiser’s page3.
5. Authority
Users are more likely to perform some act if they know some authority figure has performed that act or recommends performing that act3.
6. Scarcity
Users value objects and states of affairs higher if they believe it is in limited quantity or hard to get3.
Gulf of Execution
The amount of disparity between what a user desires to do and the systems ability to do it.1
Gulf of Evaluation
The amount of disparity between what a user needs in order to know the effects of her interaction with the system and the actual response by the system.1
Three Aspects of Design
Visceral: concerns itself with appearances.2
Behavioral: has to do with the pleasure and effectiveness of use.2
Reflective: considers the rationalization and intellectualization of a product. (self-image, personal satisfaction, memories)2
1. Donald Norman, The Design of Everyday Things (1988)
2. Donald Norman, Emotional Design (2004)
3. Robert Cialdini, Influence: Science and Practice (2001)
