Agreed, though repeated measurements weren't mentioned so I thought it was important to emphasize that finding a correlation in one measurement cannot be taken

Agreed, though repeated measurements weren't mentioned so I thought it was important to emphasize that finding a correlation in one measurement cannot be taken to imply causation, which sounded like what OP was saying. Your point is a very good one, though. If we view causation through a causal graph, such that vertices are variables and direct causal links are arrows (directed edges), a statement "correlation doesn't imply causation" can be taken to mean several things: * From correlation, we cannot determine the direction of the arrow. * From correlation, we cannot claim there *is* a (direct) arrow between two vertices. * From correlation, we cannot claim there is even a path from one vertex to the other.