An overview of the main areas of epistemological debate to which experimental philosophers have been contributing and the larger, philosophical challenges these contributions have raised.

Experimental epistemology uses experimental methods of the cognitive sciences to shed light on debates within epistemology,the philosophical study of knowledge and rationally justified belief. In this first critical collection on this exciting new subfield, leading researchers tackle key questions pertaining to knowledge, evidence, and rationally justified belief.

This chapter reviews some faults of the theoretical literature and findings from the experimental literature on “Gettier” cases. Some “Gettier” cases are so poorly constructed that they are unsuitable for serious study. Some longstanding assumptions about how people tend to judge “Gettier” cases are false. Some “Gettier” cases are judged similarly to paradigmatic ignorance, whereas others are judged similarly to paradigmatic knowledge, rendering it a theoretically useless category. Experimental procedures can affect how people judge “Gettier” cases. Some important (...) central tendencies in judging “Gettier” cases appear to be robust against demographic variation in biological sex, age, language, and culture, although there could be some interesting differences related to culture and personality traits. Some remaining questions regarding Gettier’s cases, “Gettier” cases, and “the Gettier problem” concern the psychology and sociology of contemporary anglophone theoretical epistemology. Some remaining questions regarding the empirical study of knowledge judgments concern mechanisms underlying observed behavioral patterns. (shrink)

In this paper I survey some recent developments in experimental philosophy and discuss their bearing on two leading theories in epistemology: Contextualism and Interest Relative Invariantism. In the first part of the paper, I survey some general issues of how experimental philosophy may be relevant to assessing contextualism and IRI. In the second part, I discuss and critique some of the recent experimental work.

Formal epistemology is just what it sounds like: epistemology done with formal tools. Coinciding with the general rise in popularity of experimental philosophy, formal epistemologists have begun to apply experimental methods in their own work. In this entry, I survey some of the work at the intersection of formal and experimental epistemology. I show that experimental methods have unique roles to play when epistemology is done formally, and I highlight some ways in (...) which results from formal epistemology have been used fruitfully to advance epistemically‐relevant experimental work. The upshot of this brief, incomplete survey is that formal and experimental methods often constitute mutually informative means to epistemological ends. (shrink)

It has been standard philosophical practice in analytic philosophy to employ intuitions generated in response to thought-experiments as evidence in the evaluation of philosophical claims. In part as a response to this practice, an exciting new movement—experimental philosophy—has recently emerged. This movement is unified behind both a common methodology and a common aim: the application of methods of experimental psychology to the study of the nature of intuitions. In this paper, we will introduce two different views concerning the (...) relationship that holds between experimental philosophy and the future of standard philosophical practice (what we call, the proper foundation view and the restrictionist view), discuss some of the more interesting and important results obtained by proponents of both views, and examine the pressure these results put on analytic philosophers to reform standard philosophical practice. We will also defend experimental philosophy from some recent objections, suggest future directions for work in experimental philosophy, and suggest what future lines of epistemological response might be available to those wishing to defend analytic epistemology from the challenges posed by experimental philosophy. (shrink)

This paper connects recent findings from experimental epistemology to several major themes in classical Indian epistemology. First, current evidence supports a specific account of the ordinary knowledge concept in contemporary anglophone American culture. According to this account, known as abilism, knowledge is a true representation produced by cognitive ability. I present evidence that abilism closely approximates Nyāya epistemology’s theory of knowledge, especially that found in the Nyāya-sūtra. Second, Americans are more willing to attribute knowledge of positive (...) facts than of negative facts, especially when such facts are inferred and even when the positive and negative “facts” are logically equivalent. Similar suspicions about knowledge of negative facts seemingly occur in classical Indian epistemology, suggesting that the asymmetry might not be an American quirk but instead reflect a cross-culturally robust tendency in knowledge attributions. Each of these themes—abilism and the positive/negative asymmetry—presents an exciting opportunity for further research in experimental cross-cultural epistemology. (shrink)

Formal epistemology is just what it sounds like: epistemology done with formal tools. Coinciding with the general rise in popularity of experimental philosophy, formal epistemologists have begun to apply experimental methods in their own work. In this entry, I survey some of the work at the intersection of formal and experimental epistemology. I show that experimental methods have unique roles to play when epistemology is done formally, and I highlight some ways in (...) which results from formal epistemology have been used fruitfully to advance epistemically-relevant experimental work. The upshot of this brief, incomplete survey is that formal and experimental methods often constitute mutually informative means to epistemological ends. (shrink)

This Element introduces major issues in the epistemology of experimental physics through discussion of canonical physics experiments and some that have not yet received much philosophical attention. The primary challenge is to make sense of how physicists justify crucial decisions made in the course of empirical research. Judging a result as epistemically significant or as calling for further technical scrutiny of the equipment is one important context of such decisions. Judging whether the instrument has been calibrated, and which (...) data should be included in the analysis are others. To what extent is it possible to offer philosophical analysis, systematization, and prescriptions regarding such decisions? To what extent can there be explicit epistemic justification for them? The primary aim of this Element is to show how a nuanced understanding of science in practice informs an epistemology of experimental physics that avoids strong social constructivism. (shrink)

This article examines central tensions in cybernetics, defined as the study of self-organization, communication, automated feedback in organisms, and other distributed informational networks, from its wartime beginnings to its contemporary adaptations. By examining aspects of both first- and second-order cybernetics, the article introduces an epistemological standpoint that highlights the tension between its definition as a theory of recursion and a theory of control, prediction, and actionability. I begin by examining the historical outcomes of the Macy Conferences to provide a context (...) for cybernetics’ initial development for scientific epistemology, ethics, and socio-political thought. I draw extensively from Norbert Wiener, Heinz von Foerster, Ross Ashby, and Gregory Bateson, key figures of this movement. I then elaborate upon certain premises of cybernetics to further elucidate an intellectual history from which to begin to construct a cybernetic epistemology. I conclude by offering the second-order cybernetic concept of recursivity as a model and method for ethico-epistemological questioning that can account for both the constructive potential and the limitations of cybernetics in science and society. (shrink)

Since the demise of introspective techniques in the early twentieth century, experimental psychology has largely assumed an administrative arrangement between experimenters and subjects wherein subjects respond to experimenters’ instructions and experimenters meticulously constrain that relationship through experimental controls. During the postwar era this standard arrangement came to be questioned, initiating reflections that resonated with Cold War anxieties about the nature of the subjects and the experimenters alike. Albeit relatively short lived, these interrogations of laboratory relationships gave rise to (...) unconventional testimonies and critiques of experimental method and epistemology. Researchers voiced serious concerns about the honesty and normality of subjects, the politics of the laboratory, and their own experimental conduct. Their reflective commentaries record the intimacy of subject and experimenter relations and the plentiful cultural materials that constituted the experimental situation, revealing the permeable boundaries between laboratory and everyday life. (shrink)

We employ a pragmatic model of inquiry to distinguish the epistemological character of exploratory experimentation. Exploratory experimentation is not constituted by any intrinsic characteristics of an episode of experimentation but depends on the context and aims of the experiment and the ways in which these shape decisions about how the experimental inquiry is to be conducted: its tasks, resources, and aims, as well as the critical assessment of all of these. To demonstrate the usefulness of our pragmatist model, we (...) apply it to the contrast between two kinds of searches for new physics at the Large Hadron Collider. Some searches are exploratory while others target specific Beyond Standard Model hypotheses, but this contrast can be understood only by considering the relations between these searches, their aims, and the way that these aims shape their respective experimental parameters and procedures. Our approach provides a model for establishing the epistemological significance of details of experimental practice. (shrink)

Husserl’s transcendental phenomenology is first and foremost a science of the structures of consciousness. Since it is intended to yield eidetic, i. e., a priori insights, it is often assumed that transcendental phenomenology and the natural sciences are totally detached from each other such that phenomenological investigations cannot possibly benefit from empirical evidence. The aim of this paper is to show that a beneficial relationship is possible. To be more precise, I will show how Husserl’s a priori investigations on consciousness (...) can be supplemented by research in experimental psychology in order to tackle fundamental questions in epistemology. Our result will be a phenomenological conception of experiential justification that is in accordance with and supported by empirical phenomena such as perceptual learning and the phenomenon of blindsight. Finally, I shall shed light on the systematic limits of empirical research. (shrink)

My paper draws on examples from molecular biology, the details of which I have developed elsewhere (Rheinberger 1992, 1993, 1995, 1997). Here, I can give only a brief outline of my argument. Reduction of complexity is a prerequisite for experimental research. To make sense of the universe of living beings, the modern biologist is bound to divide his world into fragments in which parameters can be defined, quantities measured, qualities identified. Such is the nature of any "experimental system." (...) Ontic complexity has to be reduced in order to make experimental research possible. The complexity of the research object, however, is epistemically retained in the rich context of an experimental landscape, where the eruption of "volcanic systems" can change the scenery dramatically as the result of particular, unprecedented findings. (shrink)

From the very beginning it was realised that quantum physics involves radically new interpretative and epistemological consequences. While hitherto there has been no satisfactory philosophical analysis of these consequences, recent years have witnessed the accomplishment of many experiments to test the foundations of quantum physics, opening up vistas to a completely novel technology: quantum technology. The contributions in the present volume review the interpretative situation, analyze recent fundamental experiments, and discuss the implications of possible future technological applications. Readership: Analytic philosophers (...) (logical empiricists), scientists (especially physicists), historians of logic, mathematics and physics, philosophers of science, and advanced students and researchers in these fields. Can be used for seminars on theoretical and experimental physics and philosophy of science, and as supplementary reading at advanced undergraduate and graduate levels. (shrink)

If pragmatism, hitherto, has been content with elaborating theories of meaning and of truth, but has neglected epistemology, there are good reasons for that neglect. For one thing, much of the accepted vocabulary of epistemological discussion begs the questions under discussion. Again, much epistemology is simply an oblique metaphysics, and not an empirical investigation of knowledge, and hence throws no light on knowing as we practice it. But another reason for this neglect lies in the very simplicity of (...) an experimental theory of knowing. Its charms are not enhanced by undulating draperies of dialectic,' nor warded by the numerological incantations of a symbolic logic, nor made elusive by recondite reference to relativity physics. Nevertheless, it is to the exposition of this elementary doctrine that I mean now to proceed. And I shall do so simply, and with seeming dogmatism, by taking the categories of field, focus, and perspective, and working them for all they are worth in an experimental epistemology... (shrink)

This essay proposes that subcultural practices such as gossip and fan writing are feminist epistemologies that can form radical archive inquiry and knowledge production, and creative outputs. Drawing on feminist new materialism and archive theory, I develop a set of principles for practice-based research methodologies that incorporate a researcher's intersubjective relationship with archive matter (e.g. records, documents, classification systems, social-material contexts) and consider the production of knowledge from such research as forms of tabulation. Fabulation here is seen as part of (...) a critically transgressive epistemological stance that expands feminist critiques of universalising master narratives and archive orthodoxies. My proposition, formed in part through a residency in the Woman's Art Library in London, is to name such research gestures ‘archive fanfiction’, where experimental and practice-oriented method moves with feminist politics and activism. (shrink)

Appeals to ordinary thought and talk are frequent in philosophy, perhaps nowhere more than in contemporary epistemology. When an epistemological theory implies serious error in “commonsense” or “folk” epistemology, it is counted as a cost of the view. Similarly, when an epistemological theory respects or vindicates deep patterns in commonsense epistemology, it is viewed as a benefit of the view. Philosophers typically rely on introspection and anecdotal social observation to support their characterizations of commonsense epistemology. But (...) recent experimental research shows that philosophers employing these methods often seriously mischaracterize commonsense. Based on these findings, I propose a fundamental change to standard practice in the field. Whether the fundamental goal of epistemology is descriptive or prescriptive, experimentation is an integral part of the project. (shrink)

My aim in this paper is to propose a way to study the role of perspectives in both the production and justification of experimental knowledge claims. My starting point for this will be Anjan Chakravartty’s claim that Ronald Giere’s perspectival account of the role of instruments in the production of such claims entails relativism in the form of irreducibly incompatible truths. This led Michela Massimi to argue that perspectivism, insofar as it wants to form a realist position, is only (...) concerned with the justification of such claims: whether they are produced reliably is, on her view, a perspective-independent fact of the matter. Following a suggestion by Giere on how scientists handle incompatible experimental results, I will then argue that Massimi’s perspectivism can be extended to also cover the production of such claims, without falling into relativism. I will elaborate this suggestion by means of Uljana Feest’s work on how scientists handle incompatible experimental results. I will argue that, if we reconceptualize perspectives as embodied and situated ways of going about in experimentation that can be made explicit through interpretation, we can obtain a fruitful understanding of the role of perspectives in both the production and justification of experimental knowledge. While this role is primarily exploratory, it can still allow for a substantial form of realism. (shrink)

Any experimental field consists of preparing special conditions for examining interesting objects for research. So naturally, the particular ways in which scientists prepare their objects determine the kind and the content of knowledge produced. This book provides a framework for the analysis of experimental practices - the Social Epistemology of Experiment - that incorporates both the ‘material’ and the ‘social’ dimensions of knowledge production. The Social Epistemology of Experiment is applied to experimental economics and in (...) so doing, it introduces the epistemic role of the participation of human subjects in experiments and the causal efficacy of institutions in constraining and enabling human behaviour. It also develops the role of the social and socially established practices in overcoming the methodological difficulties associated with experimenting with humans subjects in the social sciences as well as the effect of scientists’ interventions in the laboratory worlds. This book provides an historical and contextualized account of the emergence of experimental economics, the methodological discussions that have informed and constituted it, its main research programmes, and stylized facts. The analysis of its three main research programmes – market experiments, game theory experiments and individual decision-making experiments – shows how economics experiments are particularly tailored to produce knowledge about market institutions and individual behaviour in contexts where there might be conflicts of individual and social goals, and also about the processes of individual decision-making. (shrink)

This paper is concerned with the problem of experimental error. The prevalent view that experimental errors can be dismissed as a tiresome but trivial blemish on the method of experimentation is criticized. It is stressed that the occurrence of errors in experiments constitutes a permanent feature of the attempt to test theories in the physical world, and this feature deserves proper attention. It is suggested that a classification of types of experimental error may be useful as a (...) heuristic device in studying the nature of these errors. However, the standard classification of systematic and random errors is mathematically based does not focus on the causes of the errors, their origins, or the contexts in which they arise. A new typology of experimental errors is therefore proposed whose criterion is epistemological. This typology reflects the various stages that can be discerned in the execution of an experiment, each stage constituting a category of a certain type of experimental error. The proposed classification consists of four categories which are illustrated by historical cases. (shrink)

In recent decades many sociologists and philosophers of science, especially the so-called ‘new experimentalists’, have stressed the need for detailed studies of real, ongoing experimental practices, and have claimed that a new image of science results from such an approach. Among the new objects of interest that have emerged from laboratory studies, an important one is the tacit dimension of scientific practices. Harry Collins, in particular, has insisted that irreducibly tacit presuppositions and skills are inevitably involved in experimental (...) practices, and that these tacit resources play an essential role in the stabilization of successful scientific achievements. What I will call the ‘opacity of experimental practices’ has been analyzed in different ways, but on the whole, it has been claimed to have harmful epistemological consequences with respect to crucial issues such as the nature of experimental facts, scientific realism, scientific rationality, and the contingency of what acquires the status of an established scientific result in practitioners’ eyes. Such claims remain highly controversial. The aim of this paper is to discuss the epistemological implications of the involvement of tacit resources in experimental practices and to provide helpful conceptual tools with respect to the issue of tacit resources in science. Specifically, the paper provides an analytical clarification of the relation between the opacity of experimental practices and the principle of experimenters substitutability, the latter being a principle commonly viewed as a necessary feature of any good science. Serious doubts are finally raised about the validity of the experimenters substitutability principle, and the impact of these doubts with respect to the contingency of scientific facts and results is considered. (shrink)

Name der Zeitschrift: Nietzsche-Studien Jahrgang: 45 Heft: 1 Seiten: 56-80.

Our position is critical of the dominant method in psychology, and critical of the social use of psychological models. We assert that the scientific approach in psychology must break with modernist claim, but without sinking into post-modernist relativism. We consider that the epistemology associated with experimental psychology should be a specific epistemology associated with the particular objects studied. By calling on pragmatism and realism, psychology can find the resources to use quantitative studies as an action deployed within (...) a complex, interactive and dynamic social space, and thus break with its normative practice and function. (shrink)

If one had to identify the biggest change within the philosophical tradition in the twenty-first century, it would certainly be the rapid rise of experimental philosophy to address differences in intuitions about concepts. It is, therefore, surprising that the philosophy of medicine has so far not drawn on the tools of experimental philosophy in the context of a particular conceptual debate that has overshadowed all others in the field: the long-standing dispute between so-called naturalists and normativists about the (...) concepts of health and disease. In this paper, I defend and advocate the use of empirical methods to inform and advance this and other debates within the philosophy of medicine. (shrink)

In this first of two companion papers to a logico-mathematic, structural methodology , a meta-level analysis of the non metric structure is presented in relation to critiques based on standard experimental, statistical, and computational methods of contemporary psychology and cognitive science. The concept of a non metric methodology is examined as it relates to the epistemological and scientific goals of experimental, statistical, and computational methods. While sharing in these goals, differences and similarities between the two methodological approaches are (...) outlined. It is argued that typical experimental methods are not sufficient to extract and validate semantic information in verbal narratives. It is further suggested that a logico-mathematic, structural methodology can yield invariant law-like cognitive processes by careful methodological control of the specific case — instead of those found by current methods that produce “laws” based on statistical frequency. Lastly, the issue of experimental manipulation in relation to the logico-mathematic, structural methodology is examined. (shrink)

(1995). Heuristics, hypotheses, and social influence: A new approach to the experimental simulation of social epistemology. Social Epistemology: Vol. 9, Simulating Science, pp. 57-69.

The importance given by historian and philosopher of science Georges Canguilhem to the role of practice, techniques, and experimentation in concept-formation was largely overlooked by commentators. After placing Canguilhem’s contributions within the larger history of historical epistemology in France, and clarifying his views regarding this expression, I re-evaluate the relation between concepts and experimental practices in Canguilhem’s philosophy of science. Drawing on his early writings on the relations between science and technology in the 1930s, on the Essai sur (...) quelques problèmes concernant le normal et le pathologique , and on La formation du concept de réflexe aux XVIIe et XVIIIe siècles , I argue that the formation and rectification of concepts in Canguilhem’s sense are intrinsically bound with the experimental, material, technical, and cultural contexts in which concepts are operationalized. (shrink)

Since the heyday of ordinary language philosophy, Anglophone epistemologists have devoted a great deal of attention to the English word ‘know’ and to English sentences used to attribute knowledge. Even today, many epistemologists, including contextualists and subject-sensitive invariantists are concerned with the truth conditions of “S knows that p,” or the proposition it expresses. In all of this literature, the method of cases is used, where a situation is described in English, and then philosophers judge whether it is true that (...) S knows that p, or whether saying “S knows that p” is false, deviant, etc. in that situation. However, English is just one of over 6000 languages spoken around the world, and is the native language of less than 6% of the world’s population. When Western epistemology first emerged, in ancient Greece, English did not even exist. So why should we think that facts about the English word “know,” the concept it expresses, or subtle semantic properties of “S knows that p” have important implications for epistemology? Are the properties of the English word “know” and the English sentence ‘S knows that p’ shared by their translations in most or all languages? If that turned out to be true, it would be a remarkable fact that cries out for an explanation. But if it turned out to be false, what are the implications for epistemology? Should epistemologists study knowledge attributions in languages other than English with the same diligence they have shown for the study of English knowledge attributions? If not, why not? In what ways do the concepts expressed by ‘know’ and its counterparts in different languages differ? And what should epistemologists make of all this? (shrink)

Experimental philosophy is one of the most exciting and controversial philosophical movements today. This book explores how it is reshaping thought about philosophical method. Experimental philosophy imports experimental methods and findings from psychology into philosophy. These fresh resources can be used to develop and defend both armchair methods and naturalist approaches, on an empirical basis. This outstanding collection brings together leading proponents of this new meta-philosophical naturalism, from within and beyond experimental philosophy. They explore how the (...) empirical study of philosophically relevant intuition and cognition transforms traditional philosophical approaches and facilitates fresh ones. Part One examines important uses of traditional "armchair" methods which are not threatened by experimental work and develops empirically informed accounts of such methods that can potentially stand up to experimental scrutiny. Part Two analyses different uses and rationales of experimental methods in several areas of philosophy and addresses the key methodological challenges to experimental philosophy: Do its experiments target the intuitions that matter in philosophy? And how can they support conclusions about the rights and wrongs of philosophical views? Essential reading for students of experimental philosophy and metaphilosophy, _Experimental Philosophy, Rationalism, and Naturalism_ will also interest students and researchers in related areas such as epistemology and the philosophies of language, perception, mind and action, science and psychology. (shrink)

Philosophy is an abstract theoretical discipline. However, a new trend that develops experimental methods in philosophical research has recently been gaining popularity extending to the fields of philosophical research that have not seen experimental methods earlier. This article addresses the question of whether it is possible to investigate philosophical questions with empirical methods. Two areas of research are considered – philosophy of language and semantics and epistemology. In these subfields of philosophy, the application of experimental methods (...) has recently lead to a noticeable progress. Empirical methods are justified in those disciplines in which arguments in favor of a particular theory are based on the study of our intuitions. Experiments only serve to obtain more objective representations of our intuitions, and philosophical argumentation is built further based on these intuitions. The authors argue that the use of experimental methods in semantics is compatible with anti-psychologism about meaning. The latter point is particularly controversial because linguistic intuitions or intuitions about the meaning have often been viewed as something that speakers have clear cognitive access to. However, when experimental research (even when it is a collection of controlled judgments) shows results that are different from what the field has been previously assuming, a revision is called for. The authors review several cases of such refutations calling for further revisions and argue that such experimental work helps arguments in philosophy of language and epistemology gain more sound ground with respect to the empirical data that they build on. In philosophy of language and theoretical linguistics, the cases explored in this article relate to the differences between languages with and without articles and to the predictions about the availability of certain interpretations of such expressions or lack thereof. It is further shown how a similar method of identifying the existent or non-existent interpretations was used in the studies of the meaning of “most”. In epistemology, the article discusses the results of some recent experimental work relating to the knowledge ascriptions. The speakers’ intuitions about the famous Barn-examples have recently been shown to diverge from what philosophers have claimed, building their far-reaching arguments on the data that was arguably incorrect. (shrink)

Experimental philosophy is a relatively recent discipline that employs experimental methods to investigate the intuitions, concepts, and assumptions behind traditional philosophical arguments, problems, and theories. While experimental philosophy initially served to interrogate the role that intuitions play in philosophy, it has since branched out to bring empirical methods to bear on problems within a variety of traditional areas of philosophy—including metaphysics, philosophy of language, philosophy of mind, and epistemology. To date, no connection has been made between (...) developments in experimental philosophy and philosophy of technology. In this paper, I develop and defend a research program for an experimental philosophy of technology. (shrink)

In the past decade, experimental philosophy---the attempt at making progress on philosophical problems using empirical methods---has thrived in a wide range of domains. However, only in recent years has aesthetics succeeded in drawing the attention of experimental philosophers. The present paper constitutes the first survey of these works and of the nascent field of 'experimental philosophy of aesthetics'. We present both recent experimental works by philosophers on topics such as the ontology of aesthetics, aesthetic epistemology, (...) aesthetic concepts, and imagination, as well as research from other disciplines that not only are relevant to philosophy of aesthetics but also open new avenues of research for experimental philosophy of aesthetics. Overall, we conclude that the birth of an experimental philosophy of aesthetics is good news not only for aesthetics but also for experimental philosophy itself, as it contributes to broaden the scope of experimental philosophy. (shrink)

Experimental studies show that some corvids, apes, and rodents possess a common long-term memory system that allows them to take goal-directed actions on the basis of absent spatiotemporal contexts. In other words, evidence supports the hypothesis that Episodic Memory —far from being uniquely human— has evolved as a cross-species meaning making system. However, within this zoosemiotic breakthrough, neurocognitive studies now struggle characterizing the relations between teleological factors and phenomenological factors that would account for the episodic behavior displayed by these (...) living beings. Within such field, this paper identifies four epistemological gaps —the ‘Nagelian’, ‘de Waalian’, ‘Chomskyan’, and ‘semiotic’ gaps—, making a case for the need of a future biosemiotic model of Alloanimal Episodic Memory to come into the equation. As a whole, I conclude that experimental developments in AEM research, and philosophical advancements in biosemiotics could converge through the concept of semiosis. Introducing the latter would account for animal episodic agency as a causal influence and continuity between the above relations, outclassing the reductionist and Cartesian separation between ‘external’ bodily behavior and ‘internal’ computational operations. (shrink)

Although various statistical measures may have other valid uses, the single purpose served by statistical significance testing in the epistemology of experimental science is as a peremptory rebuttal of one potential alternative interpretation of the data.