Shackling the shoulders of giants

This paper informally summarizes a two-day symposium held at the U.S. National Academy of Sciences in Washington, D.C., September 5–6, 2002. The issue was to what extent the progress of science and societal capacity for continued technological innovation are threatened by excessive protection of intellectual property. Excessive protection creates disadvantages not only for scientists and inventors but also for educators/students and for librarians/clientele. Speakers from a variety of disciplines and institutions agreed unanimously that scientific and technological progress is, indeed, under serious threat. Various opinions were expressed about the degree of threat, currently and prospectively, as well as what counter-measures are best suited to resist undue restrictions on creative uses of scientific and technical data and information. This summary is based entirely on the author’s notes from the symposium, and the commentary offered is his alone. My apologies to the speakers if this paper does not accurately reflect the primary intent of their presentations. The “Suggested Readings” offered at the end are not specific to the speakers’ statements but rather are offered as a general resource to aid further research. The definitive record of the symposium is planned to be available from the National Academies Press as a Proceedings publication in the summer of 2003. John Gardenier is an independent researcher, ethicist and science writer.     

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.     

时间记忆层次网络模型的实验检验

实验采用分类性实验材料,使被试在对词单项目加工时形成较清晰的群集,进而形成时间组块,目的在于对时间记忆层次网络进行直接检验。其中时序判断用反时间时和正确率两种反应指标,时距估计用再现和口头估计两种方法。结果发现,时间信息记忆既存在层次网络的特征,又存在线性结构的特征。     

Thermodynamics: What One Needs to Know

Thermodynamics is the foundation of many of the topics of interest in the religion-science dialogue. Here a nonmathematical outline of the principles of thermodynamics is presented, providing a historical and conceptually understandable development that can serve teachers from disciplines other than physics. The contributions of Gibbs to both classical and rational thermodynamics, emphasizing the importance of the ensemble in statistical mechanics, are discussed. The seminal ideas of Boltzmann on statistical mechanics are contrasted to those of Gibbs in a discussion of the microscopic interpretation of the second law. The role of information theory is discussed, and the modern ideas of Prigogine and nonequilibrium are outlined in some detail with further reference to the second law. Implications for our interaction with God are considered.     

Acquisition of Related and Unrelated Factual Information Delivered by a Teacher Within an Inclusive Setting

Two secondary students with moderate disabilities (one per classroom) attended Advanced English classes with peers without disabilities in a rural high school. In additional to conducting planned daily instruction, each English teacher also systematically presented three sets of information (two facts per set) to each student with disabilities during the course of the class using a parallel treatments design. Each set of information included a fact related to the English class (e.g., Begin each sentence with a capital letter.) and a fact not related to the English class (e.g., The governor of Kentucky is Paul Patton.). The special education teacher conducted daily probe sessions to document acquisition. Of the six facts presented to each student with disabilities, one student acquired two related facts and one unrelated fact, while the other student acquired two related and two unrelated facts. This investigation implies that students who are fully included can acquire information presented by the regular classroom teacher during the course of a typical class and that teachers can facilitate learning by planning to present such information in a systematic fashion.     

Drug discrimination under a concurrent fixed-ratio fixed-ratio schedule.

Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a two-key concurrent fixed-ratio 10 fixed-ratio 40 schedule of food presentation, in which the fixed-ratio component with the lower response requirement was programmed to reinforce responding on one key after drug administration (pentobarbital-biased key) and on the other key after saline administration (saline-biased key). After responding stabilized, pigeons averaged 98% of their responses on the pentobarbital-biased key during training sessions preceded by pentobarbital, and they averaged 90% of their responses on the saline-biased key during training sessions preceded by saline. In test sessions preceded by doses of pentobarbital, chlordiazepoxide, or ethanol, pigeons switched from responding on the saline-biased key at low doses to responding on the pentobarbital-biased key at higher doses (the dose-response curve was quantal). High doses of phencyclidine produced responding on both keys, whereas pigeons responded almost exclusively on the saline-biased key after all doses of methamphetamine. These and previous experiments using concurrent reinforcement schedules to study drug discrimination illustrate that the schedule of reinforcement is an important determinant of the shape of dose-effect curves in drug-discrimination experiments.     

Satiation, capacity, and within-session responding

Responding may change substantially over the course of a session (McSweeney, Hinson, & Cannon, 1996). The role of satiation in this effect was investigated in three experiments. Experiment 1 showed that the capacity of pigeons to consume milo over a 1-hr period was relatively stable across three different methods of measurement. In Experiment 2, pigeons were divided into two groups that differed in their capacity based on one of those measures. Key pecking was then reinforced under a variable-interval 30-s schedule with hopper durations of 2 or 5 s. According to the satiation hypothesis, subjects with small capacities should satiate faster and therefore show greater decreases in food-reinforced responding than would subjects with larger capacities. The results confirmed this prediction and showed that the magnitudes of within-session decreases were better predicted by the amount an animal consumed relative to its capacity than by absolute amount alone. In Experiment 3, each pigeon was prefed 0, 5, 15, or 25 g of milo prior to each session. Consistent with the satiation hypothesis, increases in prefeeding produced lower overall response rates in the smaller capacity subjects than in the larger capacity subjects at each level of prefeeding. These experiments demonstrate the importance of a new variable in the control of behavior, and provide a recommended technique for its measurement.     

Standard errors for procrustes solutions

The asymptotic standard errors for the procrustes solutions are derived for orthogonal rotation, direct oblique rotation and indirect oblique rotation. The standard errors for the first two rotations are obtained using the augmented information matrices. For the indirect oblique solution, the standard errors of rotated parameters are derived from the information matrix of unrotated loadings using the chain rule for information matrices. For all three types of rotation, the standard errors of rotated parameters are presented for unstandardized and standardized manifest variables. Numerical examples show the similarity of theoretical and simulated values.     

SOMETHING TO OFFEND EVERYONE: TIPLER'S VISION OF IMMORTALITY

Abstract. Frank Tipler's The Physics of Immortality provides abundant cause for intellectual offense—including challenges to physics, to theology, and, seemingly, to common sense. Few philosophical conundrums remain unaddressed. Still, the book is stimulating and well presented.     

不同年级学生自然阅读过程信息加工活动特点研究

探讨不同年级学生自然阅读过程的信息加工活动特点,包括两个实验。实验１结果表明,低年级学生自然阅读后再复述文章时需要重读原文的时间比高年级学生要多,据此初步推知,低年级学生自然阅读过程可能主要是单一的语言解码信息加工活动,高年级学生自然阅读过程可能同时进行了语言解码与组织连贯的信息加工活动,以后者为主。实验２比较不同年级的学生在自然阅读、理解任务阅读与记忆任务阅读三种情况下对文章信息保持的效果,结果