dConstruct 2008: Joshua Porter, Leveraging Cognitive Bias in Social Design

Web design is now about psychology; web designers need to learn about it to create decent experiences.

"Bandwagon effect": people often do and believe things because many other people do and believe things.

Heuristics: rules of thumb which prevent us from needing to gather all information required to make a judgement. Sometimes these don't work all that well - this is cognitive bias. e.g. "Not Invented Here", prediction biases which lead to underestimates of time to work.

Seminal paper on this is "Judgement under Uncertainty: Heuristics and Biases (1974)"

Talks about a few biases:

  1. Representation Bias.
  2. Loss Aversion.
  3. Ownership Bias.

These sometimes combine: in the sign-up problem, loss avertsion and ownership bias overvalue what they use by a factor of 3. Because of ownership and prediction biases, software manufacturers overvalue their products by about 3x - so there's a combined 9x dissonance between what they want to charge and what users want to pay.

Demonstrates Freshbooks, which emphasises number of users through a worldwide map showing them (encouraging bandwagon effect).

Q: isn't this evil?
A: It's more about business ethics.

(Sounds like a "guns don't kill people, people do" type argument).

See also Duncan's talk at XPDay last year. Alan Cooper also touched on this at Agile2008.