Complex sentence: The basis of effective clicker training is precise timing to deliver the conditioned reinforcer at the same moment as the desired behaviour is offered, and then to reward with a primary reinforcer such as a treat or a toy.
Split into simpler sentences: The basis of effective clicker training is precise timing to deliver the conditioned reinforcer at the same moment as the desired behaviour is offered. The clicker is used as a'bridge' between the marking of the behaviour and the rewarding with a primary reinforcer such as a treat or a toy.