Six participants with autism learned conditional relations between complex auditory-visual sample stimuli (dictated words and pictures) and simple visual comparisons (printed words) using matching-to-sample training procedures. Pre- and posttests examined potential stimulus control by each element of the complex sample when presented individually and emergence of additional conditional relations and oral labeling. Tests revealed class-consistent performance for all participants following training.

The effects of a history of differential reinforcement for selecting a free-choice versus a restricted-choice stimulus arrangement on the subsequent responding of 7 undergraduates in a computer-based game of chance were examined using a concurrent-chains arrangement and a multiple-baseline-across-participants design. In the free-choice arrangement, participants selected three numbers, in any order, from an array of eight numbers presented on the computer screen. In the restricted-choice arrangement, participants selected the order of three numbers preselected from the array of eight by a computer program. In initial sessions, all participants demonstrated no consistent preference or preference for restricted choice. Differential reinforcement of free-choice selections resulted in increased preference for free choice immediately and in subsequent sessions in the absence of programmed differential outcomes. For 5 participants, changes in preference for choice were both robust and lasting, suggesting that a history of differential reinforcement for choice may affect preference for choice.

The current study examines agreement among individuals with varying expertise in behavior analysis about the length of baseline when data were presented point by point. Participants were asked to respond to baseline data and to indicate when to terminate the baseline phase. When only minimal information was provided about the data set, experts and Board Certified Behavior Analyst participants generated baselines of similar lengths, whereas novices did not. Agreement was similar across participants when variability was low but deteriorated as variability in the data set increased. Participants generated shorter baselines when provided with information regarding the independent or dependent variable. Implications for training and the use of visual inspection are discussed.

We evaluated the effects of differential reinforcement and accurate verbal rules with feedback on the preference for choice and the verbal reports of 6 adults. Participants earned points on a probabilistic schedule by completing the terminal links of a concurrent-chains arrangement in a computer-based game of chance. In free-choice terminal links, participants selected 3 numbers from an 8-number array; in restricted-choice terminal links participants selected the order of 3 numbers preselected by a computer program. A pop-up box then informed the participants if the numbers they selected or ordered matched or did not match numbers generated by the computer but not displayed; matching in a trial resulted in one point earned. In baseline sessions, schedules of reinforcement were equal across free-and restrictedchoice arrangements and a running tally of points earned was shown each trial. The effects of differentially reinforcing restricted-choice selections were evaluated using a reversal design. For 4 participants, the effects of providing a running tally of points won by arrangement and verbal rules regarding the schedule of reinforcement were also evaluated using a nonconcurrent multiple-baselineacross-participants design. Results varied across participants but generally demonstrated that (a) preference for choice corresponded more closely to verbal reports of the odds of winning than to reinforcement schedules, (b) rules and feedback were correlated with more accurate verbal reports, and (c) preference for choice corresponded more highly to the relative number of reinforcements obtained across free-and restricted-choice arrangements in a session than to the obtained probability of reinforcement or to verbal reports of the odds of winning.