Independence

Independence is one of the most critical concepts in probability theory. If two events are independent, the occurrence of one provides no new information about the probability of the other. This property matters greatly in both theory and practical modeling. Many statistical tests, distribution assumptions, and probabilistic models rely on some degree of independence. Yet perfect independence is rare in the real world, so it is essential to question how reasonable the assumption is. Incorrectly assuming independence can seriously distort model results.