What response times tell of children's behavior on the balance scale task

Analysis of accuracy of responses to balance scale problems gives a global idea of the cognitive processes that underlie problem-solving behavior on this task. We show that response times (RTs) provide additional detailed information about the kind and duration of these processes. We derive predictions about the RTs from Siegler's (1981) model for the balance scale task, including the counterintuitive prediction that young adults are slower than children in solving particular balance scale problems. The predictions were tested in a study in which 191 6- to 22-year-old participants were presented with a computerized balance scale task. RTs were analyzed with regression models. In addition to qualitative differences between items, we also modeled quantitative differences between items in the regression models. Analyses supported the predictions and provided additional knowledge on the rules. Rule II was reformulated as a rule that always involves the encoding, but not always the correct application of the distance cue. RTs provided evidence for the use of a buggy-rule and not an addition-rule. Finally, a relation between rule inconsistency and increased RT was found.     

Effects of alternative reinforcement on human behavior: the source does matter

Competing theories regarding the effects of delivering periodic response-independent reinforcement (more accurately, response-independent points exchanged for money) on a baseline rate of behavior were evaluated in human subjects. Contiguity theory holds that these events decrease target responding because incompatible behavior is adventitiously strengthened when the point deliveries follow target behavior closely in time. Matching theory holds that response-independent points, like any other alternative reinforcer, should reduce target responding. On this view, temporal contiguity between target responding and response-independent point delivery is unimportant. In our experiment, four different responses (moving a joystick in four different directions) were reinforced with points exchangeable for money according to four independent variable-interval schedules. Different schedules of point delivery were then superimposed on these baselines. When all superimposed point deliveries occurred immediately after one of the four responses (the target response), time allocated to target responding increased. When the superimposed point deliveries could be delivered at any time, time allocated to target responding declined and other behavior increased. When superimposed points could never immediately follow target responses, time allocated to target responding decreased further and other behavior or pausing predominated. The findings underscore the contribution of temporal contiguity in the effects of response-independent deliveries of food, money, points, etc.     

Ethics and engineering courses at Delft University of Technology: Contents, educational setup and experiences

This article reports on the development and teaching of compulsory courses on ethics and engineering at Delft University of Technology (DUT). Attention is paid to the teaching goals, the educational setup and methods, the contents of the courses, involvement of staff from engineering schools, experiences to date, and challenges for the future. The choices made with respect to the development and teaching of the courses are placed within the European and Dutch context and are compared and contrasted with the American situation and experiences. Previous versions of this article were presented at the meeting of the SEFI Working Group on Engineering Ethics in Rzeszow, Poland, April 29–May 1, 1999 and at the SEFI Annual Conference in Zurich, Switzerland, September 1–3, 1999.     

Second-order schedules of token reinforcement with pigeons: effects of fixed- and variable-ratio exchange schedules

Pigeons' key pecks produced food under second-order schedules of token reinforcement, with light-emitting diodes serving as token reinforcers. In Experiment 1, tokens were earned according to a fixed-ratio 50 schedule and were exchanged for food according to either fixed-ratio or variable-ratio exchange schedules, with schedule type varied across conditions. In Experiment 2, schedule type was varied within sessions using a multiple schedule. In one component, tokens were earned according to a fixed-ratio 50 schedule and exchanged according to a variable-ratio schedule. In the other component, tokens were earned according to a variable-ratio 50 schedule and exchanged according to a fixed-ratio schedule. In both experiments, the number of responses per exchange was varied parametrically across conditions, ranging from 50 to 400 responses. Response rates decreased systematically with increases in the fixed-ratio exchange schedules, but were much less affected by changes in the variable-ratio exchange schedules. Response rates were consistently higher under variable-ratio exchange schedules than tinder comparable fixed-ratio exchange schedules, especially at higher exchange ratios. These response-rate differences were due both to greater pre-ratio pausing and to lower local rates tinder the fixed-ratio exchange schedules. Local response rates increased with proximity to food under the higher fixed-ratio exchange schedules, indicative of discriminative control by the tokens.     

Behavioral and pharmacological variables affecting risky choice in rats.

The effects of manipulations of response requirement, intertrial interval (ITI), and psychoactive drugs (ethanol, phencyclidine, and d-amphetamine) on lever choice under concurrent fixed-ratio schedules were investigated in rats. Responding on the "certain' lever produced three 45-mg pellets, whereas responding on the "risky" lever produced either 15 pellets (p = .33) or no pellets (p .67). Rats earned all food during the session, which ended after 12 forced trials and 93 choice trials or 90 min, whichever occurred first. When the response requirement was increased from 1 to 16 and the ITI was 20 s, percentage of risky choice was inversely related to fixed-ratio value. When only a single response was required but the ITI was manipulated between 20 and 120 s (with maximum session duration held constant), percentage of risky choice was directly related to length of the ITI. The effects of the drugs were investigated first at an ITI of 20 s, when risky choice was low for most rats, and then at an ITI of 80 s, when risky choice was higher for most rats. Ethanol usually decreased risky choice. Phencyclidine did not usually affect risky choice when the ITI was 20 s but decreased it in half the rats when the ITI was 80 s. For d-amphetamine, the effects appeared to he related to baseline probability of risky choice; that is, low probabilities were increased and high probabilities were decreased. Although increase in risky choice as a function of the ITI is at variance with previous ITI data, it is consistent with foraging data showing that risk aversion decreases as food availability decreases. The pharmacological manipulations showed that drug effects on risky choice may be influenced by the baseline probability of risky choice, just as drug effects can be a function of baseline response rate.     

论学习的基本类型与教学设计──学习双机制理论的教学模式

本文阐述了学习的双机制理论关于学习的基本机制的观点,根据该学习理论对知识分类进行了新的划分,并分析了不同类型知识学习的信息加工过程与特点,然后提出了课堂学习与教学的“七阶段模型”及相应的教学设计。     

循证医学的辩证思维

随着临床医学的发展,临床医生面临着从理论知识加个人经验的医学模式向以科学证据为基础的医学模式转变。越来越多的卫生政策和诊疗指南的制定需要以高质量的研究结果为依据,如随机对照研究的结果,特别是随机对照研究的系统综述结论。循证医学模式要求医生在临床工作中不断提出问题并通过严格的科研设计来回答这些问题,同时强调不断进行知识更新,掌握最新研究证据以指导其临床工作。同时政府部门也鼓励发展循证医疗,因为它可通过研究有效的诊疗手段来提高卫生保健的效率。此外还有迹象表明法律决策过程中要参考是否遵循了研究证据和临床指南。知情的服务对象也促使临床工作者寻求研究证据作为依据,为了提高服务质量并且充分把握特殊专业领域的现状,临床工作者也需要不断了解新的依据信息。在众多的研究信息中,我们应对每项证据的研究方法、研究对象及观察的终点进行认真分析,确定该结论是否真实并适合我们的实际,从而制定有据可查的诊疗方案。     

The National Research Council Report on the Prevention of Reading Difficulties in Young Children and the Process of Dubitation

The author examines two significant issues, the adjudication of evidence and the architecture of instruction in the context of research on beginning reading. In particular, he reflects on his participation as a member of the National Research Council's committee that published the recent report entitled Preventing Reading Difficulties in Young Children (1998). The National Academy of Sciences panel of experts process is contrasted with a more explicit process for codifying scientific evidence and including quantitative experimental research as the primary source of evidence. In addition, the author argues for the importance of attending to the architecture of instruction in beginning reading.     

A Bootstrapping Model of Frequency and Context Effects in Word Learning

Prior research has shown that people can learn many nouns (i.e., word–object mappings) from a short series of ambiguous situations containing multiple words and objects. For successful cross‐situational learning, people must approximately track which words and referents co‐occur most frequently. This study investigates the effects of allowing some word‐referent pairs to appear more frequently than others, as is true in real‐world learning environments. Surprisingly, high‐frequency pairs are not always learned better, but can also boost learning of other pairs. Using a recent associative model (Kachergis, Yu, & Shiffrin, 2012), we explain how mixing pairs of different frequencies can bootstrap late learning of the low‐frequency pairs based on early learning of higher frequency pairs. We also manipulate contextual diversity, the number of pairs a given pair appears with across training, since it is naturalistically confounded with frequency. The associative model has competing familiarity and uncertainty biases, and their interaction is able to capture the individual and combined effects of frequency and contextual diversity on human learning. Two other recent word‐learning models do not account for the behavioral findings.     

Identification With All Humanity: The role of self‐definition and self‐investment

Identification With All Humanity (IWAH) relates to higher levels of concern and supportive behavior toward the disadvantaged, stronger endorsement of human rights, and stronger responses in favor of global harmony. So far, IWAH has been conceptualized as a one‐dimensional construct describing the degree with which one identifies with all humans as a superordinate ingroup. However, recent group identification models suggest a multi‐dimensional model to provide a more differentiated approach toward the understanding of the highest level of social identification. Using principal axis (Study 1) and confirmatory (Study 2) factor analyses, we suggest that IWAH sub‐divides into two dimensions—global self‐definition and global self‐investment. Study 2 revealed that global self‐investment was a stronger predictor for both convergent measures (e.g., social dominance orientation and authoritarianism) and behavioral intentions than global self‐definition. Finally, in Study 3, we manipulated IWAH to test its causal effect on donation behavior. Participants in the experimental condition, compared with the control condition, showed higher global self‐investment, which in turn predicted greater giving to global charity. These findings suggest that two dimensions with different behavioral outcomes underlie IWAH.