What are the two schedules of reinforcement that produce the highest rates of response while learning something?

Variable interval and variable ratio are the two schedules of reinforcement that produce the highest rates of response.

Variable interval is strong because you are dealing with time and it is variable, the subject doesn’t know when they would be rewarded.

Variable ratio schedules occur when a response is reinforced after an unpredictable number of responses. This schedule creates a high steady rate of response. Examples are gambling and lottery games.

The variable interval is the strongest reinforcement schedule, then variable-ratio followed by a fixed interval, then the fixed ratio followed by continuous reinforcement.