effect-cause-effecteffect-cause-effect - A method used to validate the existence of a cause-and-effect relationship for which the existence of the proposed cause is not easily provable through direct observation. This is done by proving the existence of a second effect that could only be present if the proposed cause actually exists.
Illustration: By showing that the second effect exists, the existence of the proposed common cause is demonstrated to be valid. In the logic diagram below, it is proposed that: 20 My car battery charge is low is the cause of 30 My car won't start. If it can be shown that: 40 The car's lights are very dim, that would support the existence of a low battery charge and provide reinforcement that it is the cause of the car not starting.