Chapter 7, "Intermittent Reinforcement,"
does not belong here. Its more natural and
logical place would have been in Part I, immediately
after Chapter 5 ("Operant Extinction
and Reconditioning"). That is, of course,
where Keller and Schoenfeld discussed such
"simple" schedules as Skinner's periodic conditioning
and fixed-ratio reinforcement. In
1950 it was still possible to discuss such matters
in one common chapter with material on
simple acquisition and extention.