Usability and the curse of knowledge
Elizabeth Newton, a Stanford University graduate student in psychology, conducted an experiment¹ in 1990 to demonstrate the curse of knowledge. She assigned participants to two roles: tapper and listener. The tapper would tap the rhythm of a well-known song on a table, and the listener would try to guess the song. The experiment resulted in listeners correctly guessing only 2.5% of the 120 songs tapped. Before the guesses, the tappers predicted that listeners would guess correctly 50% of the time. This discrepancy occurred because the tappers were unable to imagine what it was like not to know the tune, while the listeners could only hear a series of taps. In short: the producer of the information envisioned one in two recipients would understand the contents of the transmission, whereas the actual level of recipient understanding was one in forty.
The tappers in Newton’s experiment found it challenging to understand why the listeners had such difficulty guessing the songs. This problem occurs because once we have acquired knowledge, such as the melody of a song, it becomes difficult for us to imagine not knowing it. Consequently, we have difficulty conveying our knowledge to others because we are unable to recreate their mental state. This phenomenon is referred to as the curse of knowledge.
The curse of knowledge applies to the world of usability. UX designers need to adress the knowledge gap between the users of a system and the developers of said system. In our role as UX experts, we should do this by enhancing the signal-to-noise ratio of a user interface by overcommunicating (say, five times more than resorting to a single dimension) the meaning of contents, intent of behavior and how the system reacts to input. Analogous to the tapper, UX designers would increase the percentage probability of successfully communicating our intent to double digits. A good start.
Head on over to Youtube and try it out yourself!
[1] Newton, L. (1990). Overconfidence in the communication of intent: Heard and unheard melodies. Unpublished doctoral dissertation, Stanford University, Stanford, CA
