Although epistasis is at the center of the Fisher-Wright debate, biologists not involved in the controversy are often unaware that there are actually two different formal definitions of epistasis. We compare concepts of genetic independence in the two theoretical traditions of evolutionary genetics, population genetics and quantitative genetics, and show how independence of gene action (represented by the multiplicative model of population genetics) can be different from the absence of gene interaction (represented by the linear additive model of quantitative genetics). (...) The two formulations converge with weak selection but not with strong selection or, for multiple loci, when the aggregated interaction terms are not negligible. As a result of the different formulations of gene interaction, the presence or absence of linkage disequilibrium,/D/, does not necessarily indicate the presence or absence of fitness epistasis. Indeed, linkage disequilibrium is generated in ‘additive’ models in quantitative genetics whenever two (or more) loci experience simultaneous selection. As a research strategy, it is often practical, for theoretical or experimental reasons, to minimize gene interaction by assuming independence of gene action in regard to fitness, or by assuming linear additive effects of multiple loci on a phenotype. However, minimizing the role of epistasis in theoretical investigations hinders our understanding of the origins of diversity and the evolution of complex phenotypes. (shrink)

We develop an account of laboratory models, which have been central to the group selection controversy. We compare arguments for group selection in nature with Darwin's arguments for natural selection to argue that laboratory models provide important grounds for causal claims about selection. Biologists get information about causes and cause-effect relationships in the laboratory because of the special role their own causal agency plays there. They can also get information about patterns of effects and antecedent conditions in nature. But to (...) argue that some cause is actually responsible in nature, they require an inference from knowledge of causes in the laboratory context and of effects in the natural context. This process, cause detection, forms the core of an analogical argument for group selection. We discuss the differing roles of mathematical and laboratory models in constructing selective explanations at the group level and apply our discussion to the units of selection controversy to distinguish between the related problems of cause determination and evaluation of evidence. Because laboratory models are at the intersection of the two problems, their study is crucial for framing a coherent theory of explanation for evolutionary biology. (shrink)

Gene drives are selfish genetic elements that use a variety of mechanisms to ensure they are transmitted to subsequent generations at greater than expected frequencies. Synthetic gene drives based on the clustered regularly interspersed palindromic repeats genome editing system have been proposed as a way to alter the genetic characteristics of natural populations of organisms relevant to the goals of public health, conservation, and agriculture. Here, we review the principles and potential applications of CRISPR drives, as well as means proposed (...) to prevent their uncontrolled spread. We also focus on recent work suggesting that factors such as natural genetic variation and inbreeding may represent substantial impediments to the propagation of CRISPR drives. CRISPR-based synthetic selfish genetic elements, or gene drives, have been proposed as a means by which to genetically alter natural populations to address issues in agriculture, conservation, and public health. We describe key concepts of CRISPR gene drives and limitations that must be addressed before their use in the wild. (shrink)

We address the controversy in the literature concerning the definition of holobionts and the apparent constraints on their evolution using concepts from community population genetics. The genetics of holobionts, consisting of a host and diverse microbial symbionts, has been neglected in many discussions of the topic, and, where it has been discussed, a gene-centric, species-centric view, based in genomic conflict, has been predominant. Because coevolution takes place between traits or genes in two or more species and not, strictly speaking, between (...) species, it may affect some traits but not others in either host or symbiont. Moreover, when interacting species pairs are embedded in a larger community, indirect ecological effects can alter the expected pairwise dynamics. Mode of symbiont transmission and the degree of host inbreeding both affect the extent of microbial mixing across host lineages and thereby the degree to which selection on one trait of either partner affects other aspects of a holobiont phenotype. We discuss several potential defining criteria for holobionts using community genetics and population genetics models, suggesting their application and limitations. Using community genetics models, we show how conflict between genomes can be self-limiting, while cooperation and mutualism tend to be self-accelerating. It is likely that this bias in the evolutionary dynamics of interaction between hosts and symbionts is an important feature of holobionts. This bias in the evolutionary dynamic could contribute to explaining the absence of cheaters from natural mutualisms, although cheaters are predicted by gene-centered conflict theory to cause the evolutionary instability of mutualisms. Additionally, it may help explain the more frequent origin of mutualisms from parasitic than from free-living systems, an evolutionary trajectory opposite to that predicted by genome conflict theory. (shrink)

In a previous study, using experimental metapopulations of the flour beetle, Tribolium castaneum, we investigated phase III of Wright's shifting balance process (Wade and Griesemer 1998). We experimentally modeled migration of varying amounts from demes of high mean fitness into demes of lower mean fitness (as in Wright's characterization of phase III) as well as the reciprocal (the opposite of phase III). We estimated the meta-populational heritability for this level of selection by regression of offspring deme means on the (...) weighted parental deme means.Here we develop a Punnett Square representation of the inheritance of the group mean to place our empirical findings in a conceptual context similar to Mendelian inheritance of individual traits. The comparison of Punnett Squares for individual and group inheritance shows how the latter concept can be rigorously defined and extended despite the lack of explicitly formulated, simple Mendelian laws of inheritance at the group level. Whereas Wright's phase III combines both interdemic selection and meta-populational inheritance, our formulation separates the issue of meta-populational heritability from that of interdemic selection. We use this conceptual context to discuss the controversies over the levels of selection and the units of inheritance. (shrink)

Since Darwin, there has been a long and arduous struggle to understand the source and maintenance of natural genetic variation and its relationship to phenotype. The reason that this task is so difficult is that it requires integration of detailed, and as yet incomplete, knowledge from several biological disciplines, including evolutionary, population, and developmental genetics. In this ‘post‐genomic’ era, it is relatively easy to identify differences in the DNA sequence between individuals. However, the task remains to delineate how this abundant (...) genetic diversity actually contributes to phenotypic diversity. This necessitates tackling the problem of hidden genetic variation. Genetic polymorphisms can be conditionally cryptic, but have the potential to contribute to phenotypic variation in particular genetic backgrounds or under specific environmental conditions. A recent paper by Lauter and Doebley highlights the contribution of hidden genetic variation to traits characterizing the morphological evolution of modern maize from its wild grass‐like progenitor teosinte.1 This work is the first to demonstrate hidden variance for selected (agronomically ‘adaptive’) traits in a well‐characterized model for morphological evolution. BioEssays 24:685–689, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

Two controversies exist regarding the appropriate characterization of hierarchical and adaptive evolution in natural populations. In biology, there is the Wright-Fisher controversy over the relative roles of random genetic drift, natural selection, population structure, and interdemic selection in adaptive evolution begun by Sewall Wright and Ronald Aylmer Fisher. There is also the Units of Selection debate, spanning both the biological and the philosophical literature and including the impassioned group-selection debate. Why do these two discourses exist separately, and interact relatively little? (...) We postulate that the reason for this schism can be found in the differing focus of each controversy, a deep difference itself determined by distinct general styles of scientific research guiding each discourse. That is, the Wright-Fisher debate focuses on adaptive process, and tends to be instructed by the mathematical modeling style, while the focus of the Units of Selection controversy is adaptive product, and is typically guided by the function style. The differences between the two discourses can be usefully tracked by examining their interpretations of two contested strategies for theorizing hierarchical selection: horizontal and vertical averaging. (shrink)

Adaptive phenotypic plasticity allows organisms to cope with environmental variability, and yet, despite its adaptive significance, phenotypic plasticity is neither ubiquitous nor infinite. In this review, we merge developmental and population genetic perspectives to explore costs and limits on the evolution of plasticity. Specifically, we focus on the role of modularity in developmental genetic networks as a mechanism underlying phenotypic plasticity, and apply to it lessons learned from population genetic theory on the interplay between relaxed selection and mutation accumulation. We (...) argue that the environmental specificity of gene expression and the associated reduction in pleiotropic constraints drive a fundamental tradeoff between the range of plasticity that can be accommodated and mutation accumulation in alternative developmental networks. This tradeoff has broad implications for understanding the origin and maintenance of plasticity and may contribute to a better understanding of the role of plasticity in the origin, diversification, and loss of phenotypic diversity. (shrink)

Late in 1990, the Center for the Study of Ethics in the Professions at Illinois Institute of Technology (lIT) received a grant of more than $200,000 from the National Science Foundation to try a campus-wide approach to integrating professional ethics into its technical curriculum.! Enough has now been accomplished to draw some tentative conclusions. I am the grant's principal investigator. In this paper, I shall describe what we at lIT did, what we learned, and what others, especially philosophers, can learn (...) from us. We set out to develop an approach that others could profitably adopt. I believe that we succeeded. (shrink)

Moral sensitivity affects whether and how we see others, note moral concerns, respond with delicacy, and navigate complex social interactions. Scholars from a variety of fields explore the concept of moral sensitivity and how it develops, beginning with a natural moral capacity for sensitivity towards others that is shaped in a variety of ways through relationships, forms of teaching, and social institutions. Each of these influences alters the capacity as well as one’s responses in complex ways. The concept of moral (...) sensitivity deepens as progressive chapters demonstrate its increasing complexity through development within individuals, over time, as they mature, and as their relationships and social contexts expand. The chapters integrate research from philosophy, psychology, neuroscience, literature, education, and media and technology studies, with key chapters by Darcia Narváez, Nancy E. Snow, Michael S. Pritchard, and Stephen J. Thoma and a Foreword by Owen Flanagan. It is the only comprehensive presentation of interdisciplinary work on moral sensitivity that integrates a theoretical, methodological, and pedagogical analysis. This highly interdisciplinary approach provides a new way of thinking about the relationship of individuals to society and moral sensitivity as a social phenomenon, extending current research in ethics, moral psychology, and psychology toward situated, embodied, and contextual analyses. (shrink)

This book presents a detailed analysis of three ancient models of spatial magnitude, time, and local motion. The Aristotelian model is presented as an application of the ancient, geometrically orthodox conception of extension to the physical world. The other two models, which represent departures from mathematical orthodoxy, are a "quantum" model of spatial magnitude, and a Stoic model, according to which limit entities such as points, edges, and surfaces do not exist in (physical) reality. The book is unique in its (...) discussion of these ancient models within the context of later philosophical, scientific, and mathematical developments. (shrink)

Sceptical theists--e.g., William Alston and Michael Bergmann--have claimed that considerations concerning human cognitive limitations are alone sufficient to undermine evidential arguments from evil. We argue that, if the considerations deployed by sceptical theists are sufficient to undermine evidential arguments from evil, then those considerations are also sufficient to undermine inferences that play a crucial role in ordinary moral reasoning. If cogent, our argument suffices to discredit sceptical theist responses to evidential arguments from evil.

How does our understanding of the reality (or lack thereof ) of race as a category of being affect our understanding of racism as a social phenomenon, and vice versa? How should we envision the aims and methods of our struggles against racism? Traditionally, the Western political and philosophical tradition held that true social justice points toward a raceless future—that racial categories are themselves inherently racist, and a sincere advocacy for social justice requires a commitment to the elimination or abolition (...) of race altogether. This book focuses on the underlying assumptions that inform this view of race and racism, arguing that it is ultimately bound up in a “politics of purity”—an understanding of human agency, and reality itself, as requiring all-or-nothing categories with clear and unambiguous boundaries. Racism, being organized around a conception of whiteness as the purest manifestation of the human, thus demands a constant policing of the boundaries among racial categories. Drawing upon a close engagement with historical treatments of the development of racial categories and identities, the book argues that races should be understood not as clear and distinct categories of being but rather as ambiguous and indeterminate (yet importantly real) processes of social negotiation. As one of its central examples, it lays out the case of the Irish in seventeenth-century Barbados, who occasionally united with black slaves to fight white supremacy—and did so as white people, not as nonwhites who later became white when they capitulated to white supremacy. Against the politics of purity, Monahan calls for the emergence of a “creolizing subjectivity” that would place such ambiguity at the center of our understanding of race. The Creolizing Subject takes seriously the way in which racial categories, in all of their variety and ambiguity, situate and condition our identity, while emphasizing our capacity, as agents, to engage in the ongoing contestation and negotiation of the meaning and significance of those very categories. (shrink)

If a man born blind were to gain his sight in later life would he be able to identify the objects he saw around him? Would he recognise a cube and a globe on the basis of his earlier tactile experiences alone? This was William Molyneux's famous question to John Locke and it was much discussed by English and French empiricists in the eighteenth century as part of the controversy over innatism and abstract ideas. Dr Morgan examines the whole history (...) of this debate: Locke's own (negative) answer to the question, the contributions of Berkeley, Condillac, Diderot and Voltaire and the factual accounts of early cataract operations and modern laboratory studies. He shows how this debate is involved in the development and eventual separation of philosophy and experimental psychology after the eighteenth century and considers why the original question is effectively still unanswered. This is one problem-area with its intricate cluster of connected conceptual and technical difficulties which suggests the need for some reunion or at least collaboration between the two subjects. (shrink)

This paper criticizes the pragma-dialectical conception of a fallacy, according to which a fallacy is an argumentative speech act which violates one or more of the rules of 'rational discussion'. That conception is found to be neither a necessary nor a sufficient condition for committing a fallacy. It is also found wanting in several other respects.

It is not very surprising that it was no less true in antiquity than it is today that adult human beings are held to be responsible for most of their actions. Indeed, virtually all cultures in all historical periods seem to have had some conception of human agency which, in the absence of certain responsibility-defeating conditions, entails such responsibility. Few philosophers have had the temerity to maintain that this entailment is trivial because such responsibility-defeating conditions are always present. Another not (...) very surprising fact is that ancient thinkers tended to ascribe integrality to "what is" (to on). That is, they typically regarded "what is" as a cosmos or whole with distinguishable parts that fit together in some coherent or cohesive manner, rather than either as a "unity" with no parts or as a collection containing members (ta onta or "things that are") standing in no "natural" relations to one another. 1 The philoso phical problem of determinism and responsibility may, I think, best be characterized as follows: it is the problem of preserving the phenomenon of human agency (which would seem to require a certain separateness of individual human beings from the rest of the cosmos) when one sets about the philosophical or scientific task of explaining the integrality of "what is" by means of the development of a theory of causation or explanation ( concepts that came to be lumped together by the Greeks under the term "aitia"). (shrink)

This paper is a critical assessment of argumentum ad baculum, or appeal to force. Its principal contention is that, contrary to common opinion, there is no general fallacy of ad baculum. Most real-life ad baculums are, in fact, fairly strong. A basic logical form for reconstructed ad baculums is proposed, and a number of heterodoxical conclusions are also advanced and argued for. They include that ad baculum is not necessarily a prudential argument, that ad baculum need not involve force, violence, (...) or threats, and that one can argue ad baculum to oneself. The starting point of the paper, however, is a critical evaluation of three ad baculums from the exercise sets of Irving Copi's well-known Introduction to Logic. (shrink)

This chapter contains sections titled: Aristotle on the Infinite (to apeiron): From Cosmological Principle to Mathematical Operation Aristotle on Space: Magnitude (megethos) and Place (topos) Aristotle on Time: The “Number of Motion” and “Ever‐rolling Stream” Bibliography.

Some carnivores defend the position that the opportunistic consumption of meat is morally permissible even under the assumption that it is morally wrong to act in ways that ause unnecessary suffering to sentient beings. Ordering and consuming chicken once a week, they argue, will not increase the numbers of chickens suffering or slaughtered, since the system of purchasing and farming chickens is not sufficiently fine‐tuned to register differences at margin. We argue that, insensitivity of the market notwithstanding, consistent consequentialists are (...) morally prohibited from each additional purchase and consumption of meat. (shrink)

The existence of God as demonstrated from motion has preoccupied men in every age, and still stands as one of the critical questions of philosophic inquiry. The four thinkers Father Buckley discusses were selected because their methods of reasoning exhibit sharp contrasts when they are juxtaposed. Originally published in 1971. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts (...) of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905. (shrink)

How does our understanding of the reality (or lack thereof ) of race as a category of being affect our understanding of racism as a social phenomenon, and vice versa? How should we envision the aims and methods of our struggles against racism? Traditionally, the Western political and philosophical tradition held that true social justice points toward a raceless future--that racial categories are themselves inherently racist, and a sincere advocacy for social justice requires a commitment to the elimination or abolition (...) of race altogether. This book focuses on the underlying assumptions that inform this view of race and racism, arguing that it is ultimately bound up in a "politics of purity"--an understanding of human agency, and reality itself, as requiring all-or-nothing categories with clear and unambiguous boundaries. Racism, being organized around a conception of whiteness as the purest manifestation of the human, thus demands a constant policing of the boundaries among racial categories. Drawing upon a close engagement with historical treatments of the development of racial categories and identities, the book argues that races should be understood not as clear and distinct categories of being but rather as ambiguous and indeterminate (yet importantly real) processes of social negotiation. As one of its central examples, it lays out the case of the Irish in seventeenth-century Barbados, who occasionally united with black slaves to fight white supremacy--and did so as white people, not as nonwhites who later became white when they capitulated to white supremacy. Against the politics of purity, Monahan calls for the emergence of a "creolizing subjectivity" that would place such ambiguity at the center of our understanding of race. The Creolizing Subject takes seriously the way in which racial categories, in all of their variety and ambiguity, situate and condition our identity, while emphasizing our capacity, as agents, to engage in the ongoing contestation and negotiation of the meaning and significance of those very categories. (shrink)

The thought that human embryos could command moral respect yet also be acceptably used in medical research has struck some as incoherent. Given some assumptions about why they deserve respect, however, the thought is not objectionable, indeed not even unusual.

Some believe reality is dynamic: time passes, not just in our experience of reality, but objectively, in reality itself. There are many objections to this view. I focus on the rate objection: that time passes only if it passes at the rate of 1 second per second, but that it cannot coherently pass at that rate. Existing replies to this objection do not fully engage with its motivation. My aim is to refute the rate objection. Time can coherently pass at (...) the rate of 1 second per second. This does not conclusively show that time passes, but it removes one of the main obstacles to believing that it does. (shrink)

This paper is a critical examination of the so-called slippery slope argument for the conservative position on abortion. The argument was discussed in the philosophic literature some time back, but has since fallen into disfavor. The argument is first exposed and a general objection to it is advanced, then rebutted. Rosalind Hursthouse's more detailed and stronger objection is next aired, but also found less than convincing. In the course of discussing her objection, the correct form of the argument is identified, (...) and it's noted that rejection of the argument requires finding fault with its inductive premise. That, in turn, requires either (a) identifying and defending a cutoff point other than conception, or (b) not identifying a cutoff point but directly attacking the argument's conclusion. As far as (a) is concerned, all except one alternative cutoff point have severe problems that have been well discussed in the literature. The one that doesn't, the appearance of the ‘primitive streak’, is examined in detailed, but ultimately rejected. As for (b), five different grounds for rejecting the conclusion are identified and discussed, but none is found plausible. Variations on the slippery slope argument, concerning different conclusions that it may have, are then distinguished, related to each other, and critically discussed, and the paper ends with some cautionary remarks about the defense of the argument tendered. (shrink)

We develop a framework for assessing security market quality, relating five elements of market design to three metrics of market integrity and two metrics of market efficiency. We empirically implement this integrity–efficiency MQ framework by testing a hypothesis that trade-based ramping manipulation at the close raises execution costs on 24 security markets worldwide. Estimating a simultaneous equations model of ramping incidence, spreads, and the probability of deploying real-time surveillance, we show that quoted bid-ask spreads are positively related to the incidence (...) of MTC across seven liquidity deciles. The magnitude is economically significant; improving market integrity by cutting MTC in half reduces spreads 6–11 %. Allowing direct market access in conjunction with RTS, conducting auctions at the close, and developing regulations that require surveillance, all reduce MTC and thereby lower spreads, assuring better market integrity and enhancing market efficiency. Introducing circuit breakers or prohibiting shorts poses integrity–efficiency tradeoffs. (shrink)

Beginning at the end of the nineteenth century, systematic scientific abstracting played a crucial role in reconfiguring the sciences on an international scale. For mathematicians, the 1931 launch of the Zentralblatt für Mathematik and 1940 launch of Mathematical Reviews marked and intensified a fundamental transformation, not just to the geographic scale of professional mathematics but to the very nature of mathematicians’ research and theories. It was not an accident that mathematical abstracting in this period coincided with an embrace across mathematical (...) research fields of a distinctive form of symbolic and conceptual abstraction. This essay examines the historical, institutional, embodied, and conceptual bases of mathematical abstracting and abstraction in the mid-twentieth century, placing them in historical context within the first half of the twentieth century and then examining their consequences and legacies for the second half of the twentieth century and beyond. Focused on scale, media, and the relationship between mathematical knowledge and its forms of articulation, my analysis connects the changing social structure of modern mathematical research communities to their changing domains of investigation and resources for representation and collective understanding. (shrink)

One form of argument from analogy is identified and Stephen Barker's remarks about a second kind of argument from analogy, non-inductive (and non-deductive) argument from analogy, are used as a springboard to identify a second form. That form is then refined, explained, exemplified, and related to the first form. It is argued that there is a spectrum of different forms of argument from analogy, with the two forms identified being end points on the spectrum. Except in terms of form, however, (...) there is no reason to speak of two different kinds of argument from analogy. (shrink)

Partisan or Neutral? critically examines the Rawlsian ideal of a public, supposedly neutral, political theory meant to justify contemporary constitutional democracies. Placing this ideal-appealed to by neo-natural law theorists and advocates of "public theology" as well as by political theorists-against the background of the history of political liberalism, White shows its contradictory nature. He argues that any such legitimating theory will be 'partisan,' in the sense of appealing to convictions concerning the human good that will not be universally accepted. He (...) concludes that all politics must be imperfect-a matter of pragmatism and prudence in forming the most workable compromises possible and in acquiescing, where our principles allow us to do so, in situations that are often far from optimal. (shrink)

DESPITE THE WELL-KNOWN historical significance of Aristotle’s doctrine of the productive or active intellect it is not unusual to find contemporary discussions treating the doctrine as an excrescence on the text of the De anima, a work, it is frequently nowadays supposed, in which an otherwise securely naturalistic epistemology and rational psychology are developed. Although the doctrine of the intellectus agens is found only in one place in Aristotle’s extant texts, the third book of the De anima, I shall nonetheless (...) maintain that an argument can be ferreted out of Aristotle’s discussion that establishes that the doctrine can be seen to follow from principles that are fundamental to Aristotle’s thought. I shall call this an “Aristotelian” argument for nous poiêtikos because of the fact that the argument obviously is not found, as I state it, on the surface of Aristotle’s text. I claim that there is a significant sense in which it is there, but that one must dig for it or, as I just put it, ferret it out. In a schematic form, the Aristotelian argument goes as follows. (shrink)

A well-known epigram by Callimachus on the philosopher Diodorus Cronus reads as follows:The question of the third line, while perhaps recondite from a contemporary perspective, was clear in antiquity. The crows are asking ‘What follows ?’, in allusion to the Hellenistic disputes concerning the truth conditions of conditional propositions , disputes in which the views of Diodorus figured prominently.I agree with Sedley that the question of the last line is ‘much more problematic’. The common interpretation has been to read the (...) αθι as a form of αθις and to interpret it temporally. The result, in Pfeiffer's estimation, is ‘quomodo posthac erimus?’.This interpretation derives from Sextus Empiricus' discussion at M. 1.309–12 of the last two lines of the epigram. After crediting the grammarian with the ability to understand the allusion in the crows' first question , he proceeds to argue that the philosopher has a better chance than the grammarian of understanding the second question. But, to quote Sedley, Sextus ‘makes a ghastly mess of it’ when he attempts his own elucidation. According to an argument of Diodorus, a living thing does not die in the time in which it lives nor in a time in which it does not live. Hence, Sextus concludes, it must be the case that it never dies and, ‘if this is the case, we are always living and, according to him, we shall come to be hereafter ’. (shrink)

This paper argues that patients' duties are derivable from the idea which typically grounds the idea of patients' rights: patient autonomy. The autonomous patient, joined in partnership with the health care professional, has self-regarding obligations and obligations to others, including health care professionals. Patients' duties include, but are not limited to: a duty to be honest about why the patient seeks care; a duty to collect information on available treatments and likely side-effects; a duty for a patient who has an (...) infectious condition to act on that information which can best prevent further transmission. Keywords: autonomy, duty, paternalism, patient, rights, self-care CiteULike Connotea Del.icio.us What's this? (shrink)

This paper presents a theorisation of collaborative activity that was developed in the research field known as “collaborative learning”, in order to understand the processes of co-elaboration of meaning and knowledge. Collaboration, as distinguished from cooperation, coordination and collective activity, is defined as a continued and conjoined effort towards elaborating a “joint problem space” of shared representations of the problem to be solved. An approach to analysing the processes of co-construction of a joint problem space is outlined, in terms of (...) inter-discursive operations, together with approaches to defining different forms of cooperative activity. In conclusion, the specificity of this approach to defining collaboration is discussed in relation to other fields of research. (shrink)