For example, the chapter on reinforcement schedules was divided into two chapters, one on basic schedules and another on schedule combinations. Similarly, chapters on learning and behavior, discriminated operants, verbal behavior, and remembering have been expanded to two chapters each in the fourth edition. In general, we considered the increased number of chapters to improve the organization of the text. The chapters affected, long and densely packed in the third edition, are now more manageable for both students and instructors. Although many of the topics covered remained constant from the third to the fourth edition, as might be expected with a scientific subject matter, there are also several new topics introduced in the latest version.
Most additions are brief and are nested within sections existing in previous editions.
With 417 pages excluding references, the fourth edition is unquestionably a comprehensive text on learning. For purposes of this assessment, we defined substantial attention in two ways. First, both JEAB and JABA have published special issues or special sections that are thematic in nature. We assume that, in the judgment of the editors, selected topics are deemed important to the field. Our second test for substantial attention was more subjective.