Action-outcome contingency ($\Delta P$)

For an action $A$ and an outcome $O$, a descriptive contingency is $\Delta P=P(O\mid A)-P(O\mid \neg A)$. If both probabilities are high, outcomes may be frequent while control is absent. If both are low, outcomes may be rare while control is still absent. For causal control, actions must be experimentally varied or common causes adequately controlled; observational conditional probabilities alone can be confounded.