Pluralistic ignorance
Pluralistic ignorance can be contrasted with the false consensus effect. In pluralistic ignorance, people privately disdain but publicly support a norm (or a belief), while the false consensus effect causes people to wrongly assume that most people think like they do, while in reality most people do not think like they do (and express the disagreement openly). For instance, pluralistic ignorance may lead a student to drink alcohol excessively because she believes that everyone else does that, while in reality everyone else also wishes they could avoid binge drinking, but no one expresses that due to the fear of being ostracized. A false consensus for the same situation would mean that the student believes that most other people do not enjoy excessive drinking, while in fact most other people do enjoy that and openly express their opinion about it.
Inattentional blindness
The best-known study demonstrating inattentional blindness is the Invisible Gorilla Test, conducted by Daniel Simons of the University of Illinois at Urbana-Champaign and Christopher Chabris of Harvard University. This study, a revised version of earlier studies conducted by Ulric Neisser, Neisser and Becklen in 1975, asked subjects to watch a short video of two groups of people (wearing black and white T-shirts) passing a basketball around. The subjects are told either to count the passes made by one of the teams or to keep count of bounce passes vs. aerial passes. In different versions of the video a person walks through the scene carrying an umbrella (as discussed above) or wearing a full gorilla suit. After watching the video, the subjects are asked whether they noticed anything out of the ordinary taking place. In most groups, 50% of the subjects did not report seeing the gorilla (or the person with the umbrella). Failure to perceive the anomalies is attributed to failure to attend to it while engaged in the difficult task of counting passes of the ball. These results indicate that the relationship between what is in one's visual field and perception is based much more on attention than was previously thought.