Daily Archives: January 14, 2011

Bias: How easily we’re fooled.

In sensory science, we deal directly with extracting information from tricky and fickle systems:  humans which, as we know, are animals with brains just advanced enough to get them into trouble.  Particularly, we focus on what the subjects are experiencing from a sensorial standpoint and that, on its own, is a system which is easily confounded. This article is about the things that fool us:  the phenomena that occur around us which influence us and how we perceive reality.  It’s rather startling just how easily we can be tricked and even manipulated, and there are long and growing lists which detail our understanding of the “failures” which can be triggered in our sensory systems.  Of course these are general tendencies and not concrete rules that every human unknowingly follows.  But bias is a clear and present threat to the validity of all sensory data, and care and vigilance must be exercised by panel administrators in order to mitigate its effects.

First, we’ll discuss some of the more general ways that humans can be fooled, some of which you’ve probably seen before, then we’ll move into how it directly affects a sensory panel and even the average beer taster.

Probably one of the most famous examples of these failures of the human brain’s perception abilities is the selective attention test by Daniel Simons and Christopher Chabris from 1999. Basically the video shows you a small group of people passing basketballs back and forth and asks you to count how many times the balls are passed. If you haven’t seen it, follow that link and watch it. It’s only a minute or so long, I’ll wait here. — Great, did you see the gorilla? At one point in the video someone in a gorilla suit walks across the screen, right through the basketball game. The point of the exercise is, if you’re so attentive to the basketballs you can miss something which is right in front of you, even if it is quite absurd and out of place. It’s probably so famous that it’s hard to fall for it anymore, but it is a well documented experience.

Continue reading