Wikipedia
Thin-slicing is a term used in psychology and philosophy to describe the ability to find patterns in events based only on "thin slices," or narrow windows, of experience. The term means making very quick inferences about the state, characteristics or details of an individual or situation with minimal amounts of information. Brief judgments based on thin-slicing are similar to those judgments based on much more information. Still, judgments based on thin-slicing can be as accurate, or even more accurate than judgments based on much more information.
The first recorded use of the term was in 1992 by Nalini Ambady and Robert Rosenthal in a meta-analysis in the Psychological Bulletin. Since then, thin-slicing has been applied to many domains, and has been used to make various types of judgments. An non-exhaustive list of domains includes interpersonal relationship, clinical studies, education, etc.