The Sidman Avoidance Procedure
A) First Conditions an Escape Response $\rightarrow$

The Sidman avoidance procedure

A) first conditions an escape response without a CS, then shifts to a Pavlovian conditioning phase of CS + aversive stimulus pairings, and then tests subjects by presenting the CS only in a third phase of training.
B) involves presenting a successive, overlapping three-stimulus compound avoidance CS (e.g., light $\rightarrow$ tone $\rightarrow$ clicking $\rightarrow$ shock) and measuring which CS is the strongest reinforcer for the avoidance response.
C) presents an uncued, fixed-duration aversive stimulus (e.g., shock) at regularly occurring or fixed intervals unless a response occurs in the time between the successive scheduled aversive stimulus presentations.
D) involves classically conditioning a response to an explicit stimulus, then extinguishing that explicit stimulus, and then using that extinguished stimulus as the avoidance CS in the instrumental phase.