The terms of the upper and lower central series of a nilpotent computable group have computably enumerable Turing degree. We show that the Turing degrees of these terms are independent even when restricted to groups which admit computable orders.

This paper presents the results of computer simulations with a community of actors playing a large number of voluntarily iterated two-person-PD. The simulations are designed to enable uncooperative actors to exploit partners, leave them and find a new partner who knows nothing about their previous behavioral history. Hit-and-run exploitation should thrive under these conditions. However, as Schuessler (1989; 1990) has shown, the setting is highly unfavorable to uncooperative players. The present study extends this result to a wider set of strategies (...) which can alternatively stay with defectors {and try to improve them) or leave them quickly. In addition, a class of seemingly clever strategies is introduced which try to exploit the expected dynamics of looking for a partner. Still, a high amount of egoistical cooperation can persist in the present scenario. (shrink)

The main result of the paper states that there is a finitely presented group _G_ with decidable word problem where detection of finite subsets of _G_ which generate amenable subgroups is not decidable.

We investigate what it means for a (Hausdorff, second-countable) topological group to be computable. We compare several potential definitions based on classical notions in the literature. We relate these notions with the well-established definitions of effective presentability for discrete and profinite groups, and compare our results with similar results in computable topology.

We don't yet have adequate theories of what the human mind is representing when it represents a social group. Worse still, many people think we do. This mistaken belief is a consequence of the state of play: Until now, researchers have relied on their own intuitions to link up the conceptsocial groupon the one hand and the results of particular studies or models on the other. While necessary, this reliance on intuition has been purchased at a considerable cost. When looked (...) at soberly, existing theories of social groups are either (i) literal, but not remotely adequate (such as models built atop economic games), or (ii) simply metaphorical (typically a subsumption or containment metaphor). Intuition is filling in the gaps of an explicit theory. This paper presents a computational theory of what, literally, a group representation is in the context of conflict: It is the assignment of agents to specific roles within a small number of triadic interaction types. This “mental definition” of a group paves the way for acomputational theory of social groups– in that it provides a theory of what exactly the information-processing problem of representing and reasoning about a group is. For psychologists, this paper offers a different way to conceptualize and study groups, and suggests that a non-tautological definition of a social group is possible. For cognitive scientists, this paper provides a computational benchmark against which natural and artificial intelligences can be held. (shrink)

The main objective of this paper is the following two results. There exists a computable bi-orderable group that does not have a computable bi-ordering; there exists a bi-orderable, two-generated computably presented solvable group with undecidable word problem. Both of the groups can be found among two-generated solvable groups of derived length $3$. [a]nswers a question posed by Downey and Kurtz; answers a question posed by Bludov and Glass in Kourovka Notebook.One of the technical tools used to (...) obtain the main results is a computational extension of an embedding theorem of B. Neumann that was studied by the author earlier. In this paper we also compliment that result and derive new corollaries that might be of independent interest. (shrink)

Groups are only real, and only serve as a basis for collective action, when their members perceive them to be real. For a computational model to have analytic fidelity and predictive validity it, therefore, needs to engage with the psychological reality of groups, their internal structure, and their structuring by the social context in which they function.

Simple Heuristics That Make Us Smart invites readers to embark on a new journey into a land of rationality that differs from the familiar territory of cognitive science and economics. Traditional views of rationality tend to see decision makers as possessing superhuman powers of reason, limitless knowledge, and all of eternity in which to ponder choices. To understand decisions in the real world, we need a different, more psychologically plausible notion of rationality, and this book provides it. It is about (...) fast and frugal heuristics--simple rules for making decisions when time is pressing and deep thought an unaffordable luxury. These heuristics can enable both living organisms and artificial systems to make smart choices, classifications, and predictions by employing bounded rationality. But when and how can such fast and frugal heuristics work? Can judgments based simply on one good reason be as accurate as those based on many reasons? Could less knowledge even lead to systematically better predictions than more knowledge? Simple Heuristics explores these questions, developing computational models of heuristics and testing them through experiments and analyses. It shows how fast and frugal heuristics can produce adaptive decisions in situations as varied as choosing a mate, dividing resources among offspring, predicting high school drop out rates, and playing the stock market. As an interdisciplinary work that is both useful and engaging, this book will appeal to a wide audience. It is ideal for researchers in cognitive psychology, evolutionary psychology, and cognitive science, as well as in economics and artificial intelligence. It will also inspire anyone interested in simply making good decisions. (shrink)

Even though Pietraszewski acknowledges the tentative nature of the theory and the multiple lines of adjacent research needed to flesh it out, he insists that the finite set of primitives he identified is necessary and sufficient for defining social groups in the context of conflict. In this commentary I expose three interrelated conundrums that cast doubt on this simplistic presumption.

We study completely decomposable torsion-free abelian groups of the form $\mathcal{G}_S := \oplus_{n \in S} \mathbb{Q}_{p_n}$ for sets $S \subseteq \omega$. We show that $\mathcal{G}_S$has a decidable copy if and only if S is $\Sigma^0_2$and has a computable copy if and only if S is $\Sigma^0_3$.

There is currently much interest in bringing together the tradition of categorial grammar, and especially the Lambek calculus, with the recent paradigm of linear logic to which it has strong ties. One active research area is designing non-commutative versions of linear logic (Abrusci, 1995; Retoré, 1993) which can be sensitive to word order while retaining the hypothetical reasoning capabilities of standard (commutative) linear logic (Dalrymple et al., 1995). Some connections between the Lambek calculus and computations in groups have long (...) been known (van Benthem, 1986) but no serious attempt has been made to base a theory of linguistic processing solely on group structure. This paper presents such a model, and demonstrates the connection between linguistic processing and the classical algebraic notions of non-commutative free group, conjugacy, and group presentations. A grammar in this model, or G-grammar is a collection of lexical expressions which are products of logical forms, phonological forms, and inverses of those. Phrasal descriptions are obtained by forming products of lexical expressions and by cancelling contiguous elements which are inverses of each other. A G-grammar provides a symmetrical specification of the relation between a logical form and a phonological string that is neutral between parsing and generation modes. We show how the G-grammar can be oriented for each of the modes by reformulating the lexical expressions as rewriting rules adapted to parsing or generation, which then have strong decidability properties (inherent reversibility). We give examples showing the value of conjugacy for handling long-distance movement and quantifier scoping both in parsing and generation. The paper argues that by moving from the free monoid over a vocabulary V (standard in formal language theory) to the free group over V, deep affinities between linguistic phenomena and classical algebra come to the surface, and that the consequences of tapping the mathematical connections thus established can be considerable. (shrink)

We provide an introduction to methods and recent results on infinitely generated abelian groups with decidable word problem.

Network theory is necessary for the realization of cognitive representations and resulting empirical observations of social groups. We propose that the triadic primitives denoting individual roles are multilayer, with positive and negative relations feeding into cost–benefit calculations. Through this, we advance a computational theory that generalizes to different scales and to contexts where conflict is not present.

Python language has become the most popular computer language. Python is widely adopted in computer courses. However, Python language’s effects on the college and university students’ learning performance, motivations, computer programming self-efficacy, and maladaptive cognition have still not been widely examined. The main objective of this study is to explore the effects of learning Python on students’ programming learning. The junior students of two classes in a college are the research participants. One class was taught Java language and the other (...) class was taught Python language. The learning performance, motivations, and maladaptive cognition in the two classes were compared to evaluate the differences. The results showed that the motivations, computer programming self-efficacy, and maladaptive cognition on the learning performance were significant in the Python class. The results and findings of this study can be used in Python course arrangement and development. (shrink)

Using new techniques for controlling the categoricity spectrum of a structure, we construct a structure with degree of categoricity but infinite spectral dimension, answering a question of Bazhenov, Kalimullin and Yamaleev. Using the same techniques, we construct a computably categorical structure of non-computable Scott rank.

Social science research on the anthropomorphisms of computers and robots has been devoted to studying intellectual anthropomorphism, emotional anthropomorphism, bodily anthropomorphism, and the limits of computer and robot anthropomorphism. Although these represent important patterns for studying the anthropomorphisms of computers and robots, there are other important patterns. The limitation of anthropomorphism is one of these patterns. The limitation of anthropomorphism is a discursive practice which places limits on anthropomorphism. Discursive practices are interactional and practical activities for making sense of who (...) and what we encounter. In this article, I analyze the limitation of anthropomorphism as another important activity to investigate. Drawing on an ethnographic study of a robotics research group, I show the importance of the limitation of anthropomorphism by documenting how it contributes to research group identity. In the final section, I describe some implications for future studies of the anthropomorphisms of computers and robots. (shrink)

Theories of classification distinguish classes with some good structure theorem from those for which none is possible. Some classes (dense linear orders, for instance) are non-classifiable in general, but are classifiable when we consider only countable members. This paper explores such a notion for classes of computable structures by working out a sequence of examples. We follow recent work by Goncharov and Knight in using the degree of the isomorphism problem for a class to distinguish classifiable classes from non-classifiable. (...) In this paper, we calculate the degree of the isomorphism problem for Abelian p-groups of bounded Ulm length. The result is a sequence of classes whose isomorphism problems are cofinal in the hyperarithmetical hierarchy. In the process, new back-and-forth relations on such groups are calculated. (shrink)

The target article is an appeal to allow explicit computational theorizing into the study of social groups. Some commentators took this proposal and ran with it, some had questions about it, and some were confused or even put off by it. But even the latter did not seem to outright disagree – they thought the proposal was mutually exclusive with some other enterprise, when in fact it is not. Unfortunately, scientists studying social groups have not yet avoided the (...) thread-bare trope of the blind men studying the different parts of the elephant: We see mutual exclusivity when we should see complementarity. I hope we can all take the next steps of examining how the different enterprises and approaches within our area of research might all fit together into a unified whole. (shrink)

We welcome a computational theory on social groups, yet we argue it would benefit from a broader scope. A neuroscientific perspective offers the possibility to disentangle which computations employed in a group context are genuinely social in nature. Concurrently, we emphasize that a unifying theory of social groups needs to additionally consider higher-level processes like motivations and emotions.

A symbolic computer model, employing the perceptual strategy, is presented for solving Tower of Hanoi problems. The model is calibrated—in terms of the number of problems solved, time taken, and number of moves made—to the performance of 20 normal subjects. It is then “lesioned” by increasing the decay rate of elements in working memory to model the performance of 20 patients with lesions to the prefrontal cortex. The model captures both the main effects of subject groups (patients and normal (...) controls) performance, and the subject groups (patients and normal controls) by problem difficulty interactions. This leads us to support the working memory hypothesis of frontal lobe functions, but for a narrow range of problems. (shrink)

We compute here the Borel complexity of the relation of isometry between separable Banach spaces, using results of Gao, Kechris [2], Mayer-Wolf [5], and Weaver [8]. We show that this relation is Borel bireducible to the universal relation for Borel actions of Polish groups. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

In contrast to Pietraszewski's account, latent structure learning neither requires conflict nor relies on observation of explicit coalitional behavior to support group inference. This alternative addresses how even non-conflict-based groups may be defined and is supported by experimental evidence in human behavior.

Social kinds are heterogeneous. As a consequence of this diversity, some authors have sought to identify and analyse different kinds of social kinds. One distinct kind of social kinds, however, has not yet received sufficient attention. I propose that there exists a class of social-computation-supporting kinds, or SCS-kinds for short. These SCS-kinds are united by the function of enabling computations implemented by social groups. Examples of such SCS-kinds arereimbursement form,US dollar bill,chair of the board. I will analyse SCS-kinds, contrast (...) my analysis with theories of institutional kinds, and discuss the benefits of investigating SCS-kinds. (shrink)

Benevolent intersubjectivity developed in parent–infant interactions and compassion toward friend and foe alike are non-violent interventions to group behavior in conflict. Based on a dyadic active inference framework rooted in specific parental brain mechanisms, we suggest that interventions promoting compassion and intersubjectivity can reduce stress, and that compassionate mediation may resolve conflicts.

Incels (involuntary celibates) are part of a broader misogynistic culture known as the manosphere. Some communities within the manosphere, including incels, promote gender-based violence through misogynistic rhetoric and ideology. Incels are men who struggle to form romantic relationships and thus seek solace in online forums to find a sense of purpose and community. The community is organised around an ideology and a hierarchical classification of members. This paper presents a computational linguistic analysis of the utterances made within the community. We (...) analyse the linguistic patterns of six different ranks of users: paragons, high-rank users, low-rank users, greycels, banned users, and self-banned/deleted users. We conducted an analysis of the sentiments expressed between ranks and of the affective attitude of posters when discussing a variety of topics. We then we analysed linguistic features, also conditioned on the rank of the poster. These analyses reveal qualitative differences between users of different ranks in how they express themselves and their sentiments. Finally, we trained models based on the linguistic features of users’ posts and show that already based on this information it is possible to predict the rank of users. Overall, our results indicate that the incel community has developed distinctive linguistic patterns to disseminate their ideology and that these linguistic patterns vary according to the rank of an incel within the community. This methodology offers a robust framework for studying similar echo chamber-like communities. (shrink)

We initiate the study of computable presentations of real and complex C*-algebras under the program of effective metric structure theory. With the group situation as a model, we develop corresponding notions of recursive presentations and word problems for C*-algebras, and show some analogous results hold in this setting. Famously, every finitely generated group with a computable presentation is computably categorical, but we provide a counterexample in the case of C*-algebras. On the other hand, we show every finite-dimensional C*-algebra (...) is computably categorical. (shrink)

PurposeThe purpose of this paper is to study the ethical behaviour of Muslim IT professionals in an attempt to stop many unethical practices such as software piracy, software intellectual property violations and general software development.Design/methodology/approachThis study examines the computer ethical principles presented in the Association for Computing Machinery code of conduct from an Islamic point of view through studying some relevant verses of The Holy Quran and Hadiths of Prophet Mohammed. An evaluation of the benefits of this newly proposed Islamic (...) computer code of ethics is presented by surveying how IT students, IT professionals and software house owners would adhere to it. The evaluation was carried out by teaching different groups of participants aspects of the ACM code of conduct and the proposed Islamic computer ethics code and then surveying their opinions by a questionnaire.FindingsThe study demonstrates that teaching computer ethics in general, and computer ethics from an Islamic point of view in particular, clearly contributes to ethical behaviour of Muslim IT professionals with regards to software development issues.Research limitations/implicationsIt is not possible to put participants through real life scenarios and practically observe how they would react to different ethical situations. The empirical research thus relies on what participants said they would do.Practical implicationsThe newly developed Islamic code of computer ethics and its proposed implementation method can be utilised by organisations for their benefit.Originality/valueThe study is the first to address the issue of computer ethics and Islam for IT professionals. This paper presents a first Islamic computer code of ethics and presents a methodology for applying it. It also reports a study undertaken in Bahrain of how attitudes might be influenced by teaching computer ethics in general, and computer ethics from an Islamic point of view in particular. (shrink)

Computing as a science is the study of computers, both the hardware and their programs, and all that goes with them (Newell and Simon 1976). The philosophy of computer science is concerned with problems of a philosophical kind raised by the discipline's goals, fundamental ideas, techniques or methods, and findings. It parallels other parts of philosophy ‐ for example, the philosophy of economics or linguistics or biology ‐ in primarily considering problems raised by one discipline, rather than issues raised by (...) a group of disciplines, as does the philosophy of science in general. (shrink)

This paper reviews evidence concerning the nature of grouping in music and language and their interactions with other linguistic and musical systems. I present brief typological surveys of the relationship between constituency and acoustic parameters in language and music, drawing from a wide variety of languages and musical genres. The two domains both involve correspondence between auditory discontinuities and group boundaries, reflecting the Gestalt principles of proximity and similarity, as well as a nested, hierarchical organization of constituents. Typically, computational-level theories (...) of musical grouping take the form of a function from acoustic properties through grouping representations to syntactic or interpretive constituents. Linguistic theories tend to be cast as functions in the opposite direction. This study argues that the difference in orientation is not grounded in principled differences in information flow between the two domains, and that reconceptualizing one or both theories allows for gains in analytical understanding. There are also obvious differences between musical and linguistic grouping. Grappling with those differences requires one to think in detail about modularity, information flow, levels of description, and the functional nature of cognitive domains. (shrink)

Intelligent Tutoring Systems (ITS) has a wide influence on the exchange rate, education, health, training, and educational programs. In this paper we describe an intelligent tutoring system that helps student study computer networks. The current ITS provides intelligent presentation of educational content appropriate for students, such as the degree of knowledge, the desired level of detail, assessment, student level, and familiarity with the subject. Our Intelligent tutoring system was developed using ITSB authoring tool for building ITS. A preliminary evaluation of (...) the ITS was done by a group of students and teachers. The results were acceptable. (shrink)

This book describes a program of research in computable structure theory. The goal is to find definability conditions corresponding to bounds on complexity which persist under isomorphism. The results apply to familiar kinds of structures (groups, fields, vector spaces, linear orderings Boolean algebras, Abelian p-groups, models of arithmetic). There are many interesting results already, but there are also many natural questions still to be answered. The book is self-contained in that it includes necessary background material from recursion (...) theory (ordinal notations, the hyperarithmetical hierarchy) and model theory (infinitary formulas, consistency properties). (shrink)

Organisations are computing systems. The university’s sports centre is a computing system for managing sports teams and facilities. The tenure committee is a computing system for assigning tenure status. Despite an increasing number of publications in group ontology, the computational nature of organisations has not been recognised. The present paper is the first in this debate to propose a theory of organisations as groups structured for computing. I begin by describing the current situation in group ontology and by spelling (...) out the thesis in more detail. I then present the example of a sports centre to illustrate why one might intuitively think of organisations as computing systems. To substantiate the thesis, I introduce Piccinini’s restrictive analysis of physical computation. As I show, organisations meet all criteria for being computing systems. Organisations are structured groups with the function of manipulating medium-independent vehicles according to rules. Furthermore, I argue for the modal claim that this is a necessary feature of organisations. Having sketched the computational account of organisations, I compare it to other proposals in the literature. (shrink)

The goal of the book is to present the latest research on the new challenges of data technologies. It will offer an overview of the social, ethical and legal problems posed by group profiling, big data and predictive analysis and of the different approaches and methods that can be used to address them. In doing so, it will help the reader to gain a better grasp of the ethical and legal conundrums posed by group profiling. The volume first maps the (...) current and emerging uses of new data technologies and clarifies the promises and dangers of group profiling in real life situations. It then balances this with an analysis of how far the current legal paradigm grants group rights to privacy and data protection, and discusses possible routes to addressing these problems. Finally, an afterword gathers the conclusions reached by the different authors and discuss future perspectives on regulating new data technologies. (shrink)