Categoricity Theorems and Conceptions of Set

Two models of second-order ZFC need not be isomorphic to each other, but at least one is isomorphic to an initial segment of the other. The situation is subtler for impure set theory, but Vann McGee has recently proved a categoricity result for second-order ZFCU plus the axiom that the urelements form a set. Two models of this theory with the same universe of discourse need not be isomorphic to each other, but the pure sets of one are isomorphic to the pure sets of the other.This paper argues that similar results obtain for considerably weaker second-order axiomatizations of impure set theory that are in line with two different conceptions of set, the iterative conception and the limitation of size doctrine.     

Concurrent second-order schedules of reinforcement

Responses on one key (the main key) of a two-key chamber produced food according to a second-order variable-interval schedule with fixed-interval schedule components. A response on a second key (the changeover key) alternated colors on the main key and provided a second independent second-order variable-interval schedule with fixed-interval components. The fixed-interval component on one variable-interval schedule was held constant at 8 sec, while the fixed interval on the other variable-interval schedule was varied from 0 to 32 sec. Under some conditions, a brief stimulus terminated each fixed interval and generated fixed-interval patterns; in other conditions, the brief stimulus was omitted. Relative response rate and relative time deviated substantially from scheduled relative reinforcement rate and, to a lesser extent, from obtained relative reinforcement rate under both brief-stimulus and no-stimulus conditions. Matching was observed with equal components on both schedules; with unequal components, increasingly greater proportions of time and responses than the matching relation would predict were spent on the variable-interval schedule containing the shorter component. Preference for the shorter fixed interval was typically more extreme under brief-stimulus than under no-stimulus schedules. The results limit the extension of the matching relation typically observed under simple concurrent variable-interval schedules to concurrent second-order variable-interval schedules.     

Second-order schedules of token reinforcement: effects of varying the schedule of food presentation

In the initial link of a complex schedule, one discriminative stimulus was presented and lever pressing produced tokens on fixed-ratio schedules. In the terminal link, signalled by a second discriminative stimulus, deposits of the tokens produced food. With two rats, the terminal link was presented after each sixth component schedule of token reinforcement was completed. With the other two rats, the terminal link was presented following the first component schedule completed after a fixed interval. During the terminal link, each token deposit initially produced food. The schedule of food presentation was subsequently increased such that an increasing number of token deposits in the terminal link was required for each food presentation. Rates of lever pressing in the initial link were inversely related to the schedule of food presentation in the terminal link. These results are similar to those of experiments that have varied schedules of food presentation in chained schedules. Rates and patterns of responding controlled throughout the initial link were more similar to those ordinarily controlled by second-order brief-stimulus schedules than to those controlled by comparable extended chained schedules.     

Hack or Die: How Humanity Steers Into Its Post-Digital Future

This article introduces stories as a link between culture and evolution. It elaborates how the decline of interhuman communication leads to a loss of perception, capability for cooperation, and human intelligence and contributes to the current ecocide. It shows how cybernetics hacked the relationship between evolution and machine development, which brought forth the outlines of man’s current digital transformation and future. It suggests that Lucas Pawlik is still working on a possible sustainable future for humanity that Heinz von Foerster tried to initiate.     

On Becoming a Cybernetician: Highlights and Milestones

In this article, I describe how I encountered cybernetics and how it became an important part of my life. I begin with an account of my time at Brunel University and also describe how I came to work with Gordon Pask, one of the few intellectuals and researchers in the UK who styled themselves as cyberneticians. To enrich my story, I include an overview of the story of cybernetics as I perceive it. Given the importance I attach to cybernetics as an intellectual tool, I end with a plea for it to be included in all educational curricula.     

Shedding Dialectical Tiers: A Social-Epistemic View

Is there a duty to respond to objections in order to present a good argument? Ralph Johnson argues that there is such a duty, which he refers to as the “dialectical tier“ of an argument. I deny the (alleged) duty primarily on grounds that it would exert too great a demand on arguers, harming argumentation practices. The valuable aim of responding to objections, which Johnson 's dialectical tier is meant to satisfy, can be achieved in better ways, as argumentation is a social-epistemic activity.     

Elimination problems in logic: a brief history

A common aim of elimination problems for languages of logic is to express the entire content of a set of formulas of the language, or a certain part of it, in a way that is more elementary or more informative. We want to bring out that as the languages for logic grew in expressive power and, at the same time, our knowledge of their expressive limitations also grew, elimination problems in logic underwent some change. For languages other than that for monadic second-order logic, there remain important open problems.     

聋童与正常儿童对多种信念的认知

选取了122名3～12岁聋童,并分别用65名3～5岁的正常儿童作对照,开展了2个实验系列,探讨了儿童的正确信念、一级错误信念及二级错误信念认知的发展特点.结果如下: (1)聋童及正常儿童信念认知的发展过程中,无论是关于正确信念,还是关于一级错误信念,都是先发展自我信念认知,再发展他人信念认知;(2)关于正确信念、一级错误信念和二级错误信念认知的发展,聋童都比正常儿童滞后,但两者的发展趋势一致; (3)手语聋童在信念认知上略好于口语聋童; (4)父母为聋人或父母会手语的聋童,以及兄弟姐妹会手语的聋童,其信念认知水平要比其他聋童好.     

学前儿童欺骗及欺骗策略发展的研究

选取130名学前儿童,采用“找钱币”欺骗任务和标准误信念任务,研究学前儿童欺骗及欺骗策略的发生、发展。结果发现:随年龄增长,采用“破坏证据”和“说谎”欺骗策略的人数呈下降趋势,采用四种联合策略的人数则呈上升趋势;即使3岁儿童也能出示“破坏证据”和“说谎”这两种行为主义的欺骗策略,但“制造虚假痕迹”的心理主义欺骗策略在4岁以后才开始出现;3岁、6岁儿童的误信念理解与欺骗策略不相关,而4岁和5岁儿童的则相关。     

The Dutch Identity: A new tool for the study of item response models

The Dutch Identity is a useful way to reexpress the basic equations of item response models that relate the manifest probabilities to the item response functions (IRFs) and the latent trait distribution. The identity may be exploited in several ways. For example: (a) to suggest how item response models behave for large numbers of items—they are approximate submodels of second-order loglinear models for 2 ^J tables; (b) to suggest new ways to assess the dimensionality of the latent trait—principle components analysis of matrices composed of second-order interactions from loglinear models; (c) to give insight into the structure of latent class models; and (d) to illuminate the problem of identifying the IRFs and the latent trait distribution from sample data.This research was supported in part by contract number N00014-87-K-0730 from the Cognitive Science Program of the Office of Naval Research. I realized the usefulness of the identity in Theorem 1 while lecturing in the Netherlands during October, 1986. Because this was in no small part due to the stimulating psychometric atmosphere there, I call the result the Dutch Identity.