The behaviour directed at a stimulus (CS) that emerges during a classical conditioning procedure in which CS and unconditioned stimulus (UCS) pairings occur independently of a subject's behaviour is called autoshaping or sign‐tracking. Results of research on autoshaping are theoretically important because they suggest that classical and operant conditioning are not conceptually different processes or types of learning, but rather ought to be seen as procedures or ways of arranging learning situations. In this paper it is argued that there is only one type of learning, involving stimulus‐response (CS‐UCR) contiguity and reinforcement. The contiguity‐reinforcement hypothesis can account for the acquistion of autoshaped responding and the low levels of responding observed during omission training (in which no UCS is presented when the autoshaped response occurs) through a CS‐UCR contiguity alone. Once the initial autoshaped response occurs it is usually followed by the UCS which then acts as a reinforcer and serves to maintain r