Perceptual outcomes as reinforcers

The paucity of basic behavioral research with humans was highlighted almost 40 years ago (Findley, 1966). A recent search of the basic behavioral research journals by the present authors indicated that this situation remains, with only approximately 15% of the research using human participants. It may seem surprising that so few studies use human participants given the apparent practical advantages of doing so. Human participants are readily available, extensively pre-trained, can use a range of complex apparatus and require no feeding or housing. In reality, however, the use of human participants involves a number of practical difficulties: humans generally will not agree to participate in research involving a large number of sessions or sessions lasting more than two to three hours; it is difficult to gain within-session compliance as a result of the often repetitive and simplistic nature of the tasks; and it is often unclear whether the experimental results are a product of the experimentally-arranged contingencies or the instructions given to the participants. Another difficulty, that which is addressed here, lies in the identification of a suitable experimental outcome that will serve as a reinforcer

Precision teaching and fluency: the effects of charting and goal-setting on skaters’ performance

This research involved three successive studies where precision teaching methods were used to increase roller skaters performance rates of basic skating skills. The first study compared precision teaching methods both with and without the use of charting in a group design, and compared both within-subject and betweensubject differences for 12 skaters. Results showed that charting did not increase performance rates over that seen when charting was not used. The second study was a group design which compared two different types of goals, or performance aims, on skaters‟ performance. No difference was found between the two groups of 5 skaters when one group used a fixed, difficult goal and a second used a flexible, easier goal. In the final study, a single-subject design was used and 8 skaters completed a control condition where no goals were set before a goal was introduced for 4 skaters. It was found that an immediate increase in performance rates occurred following the introduction of the goal. Overall these three studies showed that skaters improved their performance rates over sessions, even in the absence of charting and/or goals, demonstrating that precision teaching can be applied to the sport of roller skating

Extinction-induced variability in human behavior

Participants earned points by pressing a computer space bar (Experiment 1) or forming rectangles on the screen with the mouse (Experiment 2) under differential-reinforcement-of-low-rate schedules, followed by extinction. Variability in interresponse time (the contingent dimension) increased during extinction, as for Morgan and Lee (1996); variability in diagonal length (the noncontingent dimension, Experiment 2) did not. In Experiment 3, points were contingent on rectangle size. Rectangle size and interresponse-time (the noncontingent dimension) variability increased in extinction. There was greater variability in the contingent dimension during extinction for participants with the more varied history of reinforcement in Experiment 2 but not in Experiment 3. Overall, variability in the contingent dimension increased in extinction, but the degree of increase was affected by reinforcement history

An analysis of U-Value as a measure of variability

The variability in behavior has frequently been assessed using a measure known as the U-value. Of concern in this article were the limits and constraints on U-value as a measure of variability. The relation between the U-value and aspects of variability was examined using three sets of simulated data. Our analysis demonstrates that the U-value as a measure of variability on its own fails to capture repetitive patterns in the sequence of responding. The U-value was shown to reflect the evenness of the distributions of responses across the categories/options used; however, when the number of categories actually used by the participant differed from the total number available, the relation between U-values and the number of categories allocated with responses was shown to be nonlinear. It was also shown that the same value of U can represent different levels of evenness in response distributions over categories, depending on the number of categories/options actually used. These constraints and limitations are discussed in relation to how researchers might report on behavioral variability

Weber's law and the scalar property of timing: A test of canine timing

Domestic dogs completed a temporal bisection procedure that required a response to one lever following a light stimulus of short duration and to another lever following a light stimulus of a longer duration. The short and long durations across the four conditions were (0.5–2.0 s, 1.0–4.0 s, 2.0–8.0 s, and 4.0–16.0 s). Durations that were intermediate, the training durations, and the training durations, were presented during generalization tests. The dogs bisected the intervals near the geometric mean of the short and long-stimulus pair. Weber fractions were not constant when plotted as a function of time: A U-shaped function described them. These results replicate the findings of previous research reporting points of subjective equality falling close to the geometric mean and also confirm recent reports of systematic departures from Weber’s law

Matching-to-sample and stimulus-pairing-observation procedures in stimulus equivalence: The effects of number of trials and stimulus arrangement

Studies comparing the effectiveness of the stimulus-pairing-observation and matching-to-sample procedures in facilitating equivalence relations have reported conflicting findings. This study compared the effectiveness of these procedures and examined the effect of stimulus arrangement and the number of training trials completed prior to each exposure to tests for symmetry and equivalence. Overall, the matching-to-sample procedure resulted in a greater percentage of participants demonstrating equivalence, and with fewer training trials, than did the stimulus-pairing-observation procedure. The one-to-many stimulus arrangement was more effective than the many-to-one and linear arrangements, overall. However, there was an interaction between the type of training procedure and stimulus arrangement. Participants who completed 120 training trials prior to each test were more likely to demonstrate equivalence than participants who completed 60 trials. This appeared to be the result of completing a greater number of trials prior to each test rather than of the number of training trials completed overall

Timing of reinforcement during dog training

Research on dog-human communication has demonstrated that dogs are extremely responsive to human cues such as pointing, eye gazing and vocalizations. Because dogs are so receptive to such cues, it is reasonable to assume that subtle feedback from humans has an effect on the efficacy of dog training. Timing of reinforcement in the field of dog behavior has not been researched extensively. Research on other species has demonstrated that although animals can learn tasks with delays to reinforcement, longer delays result in longer average times to task acquisition and relatively lower rates of responding. The aim of this study was to examine owners’ latencies to providing reinforcers for their dogs’ responses during basic dog training. Video observations were made at three New Zealand dog obedience clubs. Fifteen people volunteered to take part in this study with their dogs. All participants were members of beginner classes and were videoed while training their dogs in class. Behaviors appropriate for examining the timing of reinforcement required a clearly-definable start and finish point, so ‘sit’ and ‘down’ were chosen for analysis. Times were measured between the owners’ commands, the dogs’ responses, secondary reinforcement (verbal praise), and primary reinforcement (food). Preliminary analysis of data from seven participants shows that dogs were reinforced for responding correctly to 27% of commands. These events were used for timing analysis. In addition, the dogs responded correctly but received no reinforcer of any type for 31% of commands, they responded incorrectly to 2% of commands and 40% of commands elicited no response from the dogs. There was considerable variation across participants’ timing of reinforcement with the latency to deliver the first instance of reinforcement (secondary or primary) ranging from 0 to > 5 seconds. No significant difference was found between owners’ latency to deliver secondary or primary reinforcement (t (5) = −1.66, P = 0.16) or between the times taken to reinforce ‘sit’ or ‘down’ responses (t (5) = −0.65, P = 0.54) (first instance of reinforcement). Results showed a positive correlation between the time to the first instance of reinforcement and the proportion of incorrect responses (r (7) = 0.65, P = 0.12). We conclude that given the wide range of latencies to reinforcement, it is possible that the dogs’ task acquisition was suboptimal at times. Delays to reinforcement may also give room for unintentional feedback to occur, particularly as dogs are so receptive to human-given cues. Ongoing research will attempt to address these questions

Physics and technology of the Next Linear Collider: a report submitted to Snowmass '96

We present the current expectations for the design and physics program of an e+e- linear collider of center of mass energy 500 GeV -- 1 TeV. We review the experiments that would be carried out at this facility and demonstrate its key role in exploring physics beyond the Standard Model over the full range of theoretical possibilities. We then show the feasibility of constructing this machine, by reviewing the current status of linear collider technology and by presenting a precis of our `zeroth-order' design