Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Why a contingency or correlation is not simply a temporal relation. The 2-by-2 table shows the conjunctions possible of the presence and absence of two events, E1 and E2. A positive contingency holds between E1 and E2 only if two conjunctions occur with high probability at different times: the presence of both and the absence of both (indicated by checks). The conjunction of the two alone (contiguity) cannot suffice.
