X-Nico

Info-gap decision theory

For instance, a simple model of daily stock market returns – which by definition fall in the range $-100\backslash \%,+\backslash infty\backslash \%)$ – may include extreme moves such as Black Monday (1987) but might not model the market breakdowns following the September 11 attacks: it considers the "known unknowns", not the "unknown unknowns".

see also