Sidman, M. (2001). Safe periods both explain and need explaining. Journal of the Experimental Analysis of Behavior, 75, 335-365.

Dinsmoor’s (2001) stress on the response-produced safe period as a reinforcer for avoidance behavior is a positive contribution, even though several questions about such safe periods remain to be answered.

Key words: avoidance behavior, free-operant avoidance, safe period, response-produced stimulation, shock density