In this paper, I will argue that, while the ethical issues raised by cluster randomization can be challenging, they are not new. My thesis divides neatly into two parts. In the first, easier part I argue that many of the ethical challenges posed by cluster randomized human subjects research are clearly present in other types of human subjects research, and so are not novel. In the second, more difficult part I discuss the thorniest ethical challenge for cluster (...) randomized research – cases where consent is genuinely impractical to obtain. I argue that once again these cases require no new analytic insight; instead, we should look to political philosophy for guidance. In other words, the most serious ethical problem that arises in cluster randomized research also arises in political philosophy. (shrink)

The aim of the article is to trace the integration of education, science and production through the development of regional cluster policy. At the present stage of development of postindustrial society in the global economy, the processes of globalization and specialization of national markets significantly increase competition between countries, between regions and between producers within the country. In these circumstances, the state authorities of the Russian Federation, while maintaining global leadership in the energy sector, define as long-term development goals (...) of the country, the creation of a competitive economy based on knowledge and high technologies. Following this doctrine in the Russian regions in the period from 2012 to 2014 cluster policy is implemented on the basis of Federal and regional innovation strategies. An important role in this process belongs to the activities of leading higher educational institutions - national research universities, which contribute to stimulate an active scientific activity of students and the introduction of scientific achievements into production. One of the pilot cluster projects, funded by the Federal budget became the territorial cluster ‘ Pharmaceutics, medical technology and information technology ‘ formed in the Tomsk region with a unique starting opportunities for the development of sustainable regional innovation system is a developed scientific and educational complex, small and medium-sized innovative enterprises with the latest technological developments in pharmaceuticals and medical technology. In two years, the activity cluster, implemented with the financial support of public authorities, has been successful. In the future, there are plans to expand the range of pharmaceutical products and the collaboration with other clusters Tomsk. Cluster policy contributes to the emergence of stakeholders and large economic enterprises, thus providing a close relationship between science, business and regional authorities. (shrink)

Regier, Kay, and Khetarpal report the results of computer simulations that cluster color stimuli on the basis of their coordinates in CIELAB space, one of two commonly used perceptual color spaces. Regier and coauthors find partitions of those stimuli that are strikingly similar to the way actual color lexicons partition color space. They do not argue for the custom-made clustering method used in their simulations, nor for the assumption of CIELAB space. The present paper aims to answer the question (...) to what extent their computational results depend on these assumptions. It does this by applying a great variety of known clustering methods to Regier et al.’s stimuli, and by assuming not only CIELAB space but also CIELUV space, the other main color space. (shrink)

Clustering plays an important role in data mining, pattern recognition, and machine learning. Single-valued neutrosophic sets are useful means to describe and handle indeterminate and inconsistent information that fuzzy sets and intuitionistic fuzzy sets cannot describe and deal with. To cluster the data represented by single-valued neutrosophic information, this article proposes single-valued neutrosophic clustering methods based on similarity measures between SVNSs. First, we define a generalized distance measure between SVNSs and propose two distance-based similarity measures of SVNSs. Then, we (...) present a clustering algorithm based on the similarity measures of SVNSs to cluster single-valued neutrosophic data. Finally, an illustrative example is given to demonstrate the application and effectiveness of the developed clustering methods. (shrink)

The cluster account, one of the best attempts at art classification, is guilty of ahistoricism. While cluster theorists may be happy to limit themselves to accounting for what art is now rather than how the term was understood in the past, they cannot ignore the fact that people seem to apply different clusters when judging art from different times. This paper shows that while allowing for this kind of historical relativity may be necessary to save the account, doing (...) so could result in incorporating an essentially institutional component or making the theory extremely complex and virtually impossible to use. (shrink)

The emergence of new technologies such as the Internet of things and the Cloud transforms the way we interact. Whether it be human to human interaction or human to machine interaction, the size of the networks keeps growing. As the networks get more complex nowadays with many interconnected components, it is necessary to develop distributed scalable algorithms so as to minimize the computation required in decision making in such large-scale systems. In this paper, we consider a setup where each agent (...) in the network updates its opinion by relying on its neighbors’ opinions. The information exchange between the agents is assumed to be mutual. The cluster consensus problem is investigated for networks represented by static or time-varying graphs. Joint and integral connectivity conditions are utilized to determine the number of clusters that are formed, as the interactions among the agents evolve over time. Finally, some numerical examples are given to illustrate the theoretical results. (shrink)

ABSTRACT: The cluster theory of names is generally thought to have been to have been utterly discredited by the objections raised against it by Kripke in Naming and Necessity. In this paper, I develop a new version of the cluster theory in which the role played by clusters of associated descriptions is occupied by teams of cognitive relations. And I argue that these teams of relations find a home in an account of the meanings of expressions in epistemic (...) sentence frames, and in a more general theory of the reference of proper names. RÉSUMÉ: La théorie des faisceaux de noms est généralement considérée sans fondement depuis les objections soulevées par Kripke dans Naming and Necessity. Nous proposons une nouvelle version de la théorie des faisceaux dans laquelle le rôle joué par les faisceaux de descriptions associées est pris en charge par des équipes de relations cognitives. Ces équipes de relations trouvent leur place au sein de l’explication de la signification des expressions dans le cadre de phrases épistémologiques et, plus généralement, dans celui d’une théorie de la référence des noms propres. (shrink)

In this paper, we present our research on data mining approaches with the existence of obstacles. Although there are a lot of algorithms designed to detect clusters with obstacles, few algorithms can detect clusters and outliers simultaneously and interactively. We here extend our original research [Shi, Zhang, Towards Exploring Interactive Relationship between Clusters and Outliers in Multi-Dimensional Data Analysis, 518–519: IEEE Computer Society, 2005] on iterative cluster and outlier detection to study the problem of detecting cluster and outliers (...) iteratively with the presence of obstacles. Clusters and outliers are concepts of the same importance, so it is necessary to treat clusters and outliers in the same way in data analysis. In this algorithm, clusters are detected and adjusted according to the intra-relationship within clusters and the inter-relationship between clusters and outliers, and vice versa. The adjustment and modification of the clusters and outliers are performed iteratively until a certain termination condition is reached. This data processing algorithm can be applied in many fields such as pattern recognition, data clustering and signal processing. (shrink)

Noah Rosenberg et al.'s 2002 article “Genetic Structure of Human Populations” reported that multivariate genomic analysis of a large cell line panel yielded reproducible groupings (clusters) suggestive of individuals' geographical origins. The paper has been repeatedly cited as evidence that traditional notions of race have a biological basis, a claim its authors do not make. Critics of this misinterpretation have often suggested that it follows from interpreters' personal biases skewing the reception of an objective piece of scientific writing. I contend, (...) however, that the article itself to some degree facilitates this misrepresentation. I analyze in detail several verbal and visual features of the original article that may predispose aspects of its racial interpretation; and, tracing the arguments of one philosopher and one popular science writer, I show how these features are absorbed, transformed into arguments for a biological basis of race, and re-attributed to the original. The essay demonstrates how even slight ambiguities can enable the misappropriation of scientific writing, unintentionally undermining the authors' stated circumspection on the relationship between cluster and race. (shrink)

BACKGROUND: There is growing interest in the ethics of cluster trials, but no literature on the uncertainties in defining communities in relation to the scientific notion of the cluster in collaborative biomedical research. METHODS: The views of participants in a community-based cluster randomised trial (CRT) in Mumbai, India, were solicited regarding their understanding and views on community. We conducted two focus group discussions with local residents and 20 semi-structured interviews with different respondent groups. On average, ten participants (...) took part in each focus group, most of them women aged 18-55. We conducted semi-structured interviews with ten residents (nine women and one man) lasting approximately an hour each and seven individuals (five men and two women) identified by residents as local leaders or decision-makers. In addition, we interviewed two Municipal Corporators (locally elected government officials involved in urban planning and development) and one representative of a political party located in a slum community. RESULTS: Residents' sense of community largely matched the scientific notion of the cluster, defined by the investigators as a geographic area, but their perceived needs were not entirely met by the trial. CONCLUSION: We examined whether the possibility of a conceptual mismatch between 'clusters' and 'communities' is likely to have methodological implications for a study or to lead to potential social disharmony because of the research interventions, arguing that it is important to take social factors into account as well as statistical efficiency when choosing the size and type of clusters and designing a trial. One method of informing such a design would be to use existing forums for community engagement to explore individuals' primary sense of community or social group and, where possible, to fit clusters around them. (shrink)

The paper presents different clustering approaches in legal judgments from the Special Civil Court located at the Federal University of Santa Catarina. The subject is Consumer Law, specifically cases in which consumers claim moral and material compensation from airlines for service failures. To identify patterns from the dataset, we apply four types of clustering algorithms: Hierarchical and Lingo, K-means and Affinity Propagation. We evaluate the results based on the following criteria: entropy and purity; algorithm's ability in providing labels; legal expert’s (...) evaluation; and experimental complexity. The results demonstrate that the most advantageous approach is Hierarchical Clustering, since it has the best entropy and purity numbers, as well as the least difficulty for the expert to analyze the clusters, and the least experimental complexity. The main contribution of the paper is to show the advantages and disadvantages of each approach, especially to identify labels in unstructured and non-indexed legal texts. (shrink)

The Automated External Defibrillator (AED) is an intuitive device used by witnesses of an incident without medical training in cases of sudden cardiac arrest. Its operation consists in delivering an electrical pulse to the cardiac conduction system, as a result of which normal heart rate is restored. The lack of awareness in society concerning the usefulness of the device and the inadequate deployment of AEDs result in their too infrequent application by witnesses of incidents. The aim of this paper is (...) to verify whether cluster analysis is the appropriate statistical method to determine the appropriate deployment of AED devices on the basis of cases of sudden cardiac arrest in out-of-hospital conditions. The initial cluster analysis showed the validity of using the method in question for planning the appropriate locations of AEDs. (shrink)

The gain of a selective advantage in cancer as well as the establishment of complex traits during evolution require multiple genetic alterations, but how these mutations accumulate over time is currently unclear. There is increasing evidence that a mutator phenotype perpetuates the development of many human cancers. While in some cases the increased mutation rate is the result of a genetic disruption of DNA repair and replication or environmental exposures, other evidence suggests that endogenous DNA damage induced by AID/APOBEC cytidine (...) deaminases can result in transient localized hypermutation generating simultaneous, closely spaced (i.e. “clustered”) multiple mutations. Here, we discuss mechanisms that lead to mutation cluster formation, the biological consequences of their formation in cancer and evidence suggesting that APOBEC mutagenesis can also occur genome‐wide. This raises the possibility that dysregulation of these enzymes may enable rapid malignant transformation by increasing mutation rates without the loss of fitness associated with permanent mutators. (shrink)

This article contributes to literature on corporate social responsibility exhibited by industrial clusters in developing countries. The authors conceptualize and empirically investigate the role of donor-funded CSR initiatives aimed at promoting collective action by cluster-based small- and medium-sized enterprises. A case study of the Sialkot football-manufacturing cluster in Pakistan indicates that donor-funded support of CSR initiatives in industrial clusters in developing countries may be short-lived, due to the political economy of aid, the national context of CSR implementation, tensions (...) within SME networks, and negative perceptions of CSR by the cluster-based SMEs themselves. The findings and implications of this analysis can inform both research and policy making in this area. (shrink)

Berys Gaut has recently defended a cluster account of art. He proposes it as superior to other anti-essentialist positions. I argue that his defence of this claim is unconvincing. Not only is the cluster theory consistent with the current crop of disjunctive definitions, it is at its most plausible when seen in such terms.

Berys Gaut has recently articulated and defended a putatively anti-definitional ‘cluster’ theory of art. In the first part of this paper, I argue that Gaut's version of the cluster account is flawed. The key notion of ‘counting toward the application of a concept’ is formulated in such a way that a range of apparently irrelevant properties will count as criterial for the concept of art. Moreover, there does not appear to be any quick fix to this problem. I (...) then turn to an exploration of the relationship between the cluster theory and the possibility of defining art. Gaut has claimed that the truth of the cluster account would provide an independent basis for rejecting the possibility of an adequate definition of art. I argue that this is not the case. But while the truth of the cluster account is consistent with definition, I also argue that it would not entail the definability of art in any ordinary sense. (shrink)

Individuals with trypophobia have an aversion towards clusters of roughly circular shapes, such as those on a sponge or the bubbles on a cup of coffee. It is unclear why the condition exists, given the harmless nature of typical eliciting stimuli. We suggest that aversion to clusters is an evolutionarily prepared response towards a class of stimuli that resemble cues to the presence of parasites and infectious disease. Trypophobia may be an exaggerated and overgeneralised version of this normally adaptive response. (...) Consistent with this explanation, individuals with trypophobia, as well as comparison individuals, reported aversion towards disease-relevant cluster stimuli, but only the trypophobic group reported aversion towards objectively harmless cluster stimuli that had no relevance to disease. For both groups the level of aversion reported was predicted uniquely by a measure of disgust sensitivity. Scaled emotion ratings and open-ended responses revealed that the aversive response was predominantly based on the disease avoidance emotion, disgust. Many open-ended responses also described skin sensations. These findings support the proposal that individuals with trypophobia primarily perceive cluster stimuli as cues to ectoparasites and skin-transmitted pathogens. (shrink)

This paper replies to objections from Thomas Adajian, Stephen Davies, and Robert Stecker to my claim, defended in ‘"Art" as a Cluster Concept’, that ‘art’ is a cluster concept and so cannot be defined. The paper also clarifies and extends the arguments of the earlier paper and locates its position in relation to the work of Morris Weitz.

Hidden cluster problems can manifest when broad ethnic categories are used as proxies for cultural traits, especially when traits are assumed to encode cultural distances between groups. We suggest a granular understanding of cultural trait distributions within and between ethnic categories is fundamental to the interpretation of heritability estimates as well as general behavioral outcomes.

Clustering algorithm is one of the important research topics in the field of machine learning. Neutrosophic clustering is the generalization of fuzzy clustering and has been applied to many fields. This paper presents a new neutrosophic clustering algorithm with the help of regularization. Firstly, the regularization term is introduced into the FC-PFS algorithm to generate sparsity, which can reduce the complexity of the algorithm on large data sets. Secondly, we propose a method to simplify the process of determining regularization parameters. (...) Finally, experiments show that the clustering results of this algorithm on artificial data sets and real data sets are mostly better than other clustering algorithms. Our clustering algorithm is effective in most cases. (shrink)

A model is proposed that deals with the observed collinearities (spatial, temporal and quantitative) of Hox gene expression during pattern formation along the primary and secondary axes of vertebrates. In particular, in the proximodistal axis of the developing limb, it is assumed that a morphogen gradient is laid down with its source at the distal tip of the bud. The extracellular signals in every cell of the morphogenetic field are transduced and uniformly amplified so that molecules are produced in the (...) nucleus with appropriate physicochemical properties. These molecules can exert a concentration‐dependent force on the Hox cluster. It is assumed that, before activation, the Hox cluster is packaged as an elongated rigid body inside the chromatin and is covered by a coat that prevents the transcription factors reaching the genes of the cluster. The transcription factors are confined to the interchromatin domain and their density decreases with their distance from the chromatin surface. A gradual increase in the extracellular morphogen concentration causes a corresponding increase in the number of the nuclear molecules and the resulting bigger force pushes the Hox cluster toward the interchromatin domain. The step‐by‐step translocations of the Hox cluster initiate the consecutive exposure of genes to their transcription factors. The model explains how gene activation is triggered and it describes spatial, temporal and quantitative collinearities at the initial stages of gene expression. Some recent experiments of Hox deletions and duplications are accounted for by the model. BioEssays 26:189–195, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

BackgroundSome children appear to not hear well in class despite normal hearing sensitivity. These children may be referred for auditory processing disorder (APD) assessment but can also have attention, language, and/or reading disorders. Despite presenting with similar concerns regarding hearing difficulties in difficult listening conditions, the overall profile of deficits can vary in children with suspected or confirmed APD. The current study used cluster analysis to determine whether subprofiles of difficulties could be identified within a cohort of children presenting (...) for auditory processing assessment.MethodsNinety school-aged children (7–13 years old) with suspected APDs were included in a cluster analysis. All children had their reading, language, cognition and auditory processing assessed. Parents also completed the Children’s Auditory Performance Scale (CHAPS). Cluster analysis was based on tasks where age-norms were available, including word reading (Castles and Coltheart irregular and non-words test), phonological awareness (Queensland University Inventory of Literacy), language [Comprehensive Language of Assessment-4, Comprehensive Assessment of Spoken Language (CASL)], sustained attention (Continuous Performance Test), working memory (digits forward and backward), and auditory processing [Frequency Pattern Test (FPT), Dichotic Digits Test (DDT)]. Hierarchical cluster analysis was undertaken to determine the optimal number of clusters for the data, followed by... (shrink)

The cluster account of art is a purportedly non-definitional account of art, inspired by Wittgenstein's notion of family resemblance, and recently defended by Berys Gaut. Gaut does not provide good reasons to think that art is not definable, and his approach to possible counterexamples to the cluster account would, applied consistently, preclude this. The cluster account's theory of error, its resources for accounting for borderline cases, and its heuristic usefulness are not impressive. Reasons strong enough to warrant (...) accepting the cluster account, it is concluded, have not been given. (shrink)

A recent concern in the debate on corporate social responsibility (CSR) in developing countries relates to the tension between demands for CSR compliance found in many global value chains (GVCs) and the search for locally appropriate responses to these pressures. In this context, an emerging and relatively understudied area of interest relates to small firm industrial clusters. Local clusters offer the potential for local joint action, and thus a basis for improving local compliance on CSR through collective monitoring and local (...) governance. This article explores the interrelationship between global governance, exercised through GVC ties, and local governance, via cluster institutions, in ensuring compliance with CSR pressures. It undertakes a comparative analysis of two leading export-oriented football manufacturing clusters in South Asia that have both faced common challenges on child labour. The article shows that both forms vertical and horizontal governance have played a part in shaping the response of the two clusters on child labour. Moreover, these two distinct forms of governance have also led to quite differentiated outcomes in terms of forms of work organization and child labour monitoring. This raises broader questions on how global CSR demands can locally be better embedded and the conditions under which football stitchers labour in these new work forms. (shrink)

Although there once was a general consensus among race scholars that applying race categories to humans is biologically illegitimate, this consensus has been erased over the past decade. This is largely due to advances in population genetics that allow biologists to pick out genetic population clusters that approximate some of our common sense racial categories. In this paper, I argue that this new ability really ought not undermine our confidence in the biological illegitimacy of the human races. Unfortunately, the claim (...) that races are biologically legitimate is ambiguous—the sense I will be concerned with here holds that the human species can be divided into biological subspecies. Sesardic and Andreasen have both argued that the cluster results are evidence for subspecies within the human population. I show the cluster results are in fact evidentially inert relative to each author’s preferred subspecies concept. I then sketch the kinds of biological facts that could be used to adjudicate whether human subspecies have existed in the past. (shrink)

The nature of the process of meaning-making in science has been one of the central problems in the philosophy of science of the 20th century. Yet, in spite of strenuous efforts by many able philosophers and historians of science over the past three decades or so, our understanding of this process continues to be unsatisfactory and fragmented at best. The need for an adequate account has been particularly exacerbated by the "infamous" and often misinterpreted problem of incommensurability , and its (...) alleged consequence, the incomparability of scientific theories--which presumably threatens the rationality, objectivity, and progress of science. ;In this project, I argue that a new and revised cluster theory can be articulated, which meets the objections typically raised against traditional theories of meaning and theories of reference . Such a theory is not only based on more plausible assumptions and principles, but, in addition, it satisfies the main adequacy requirements formulated by proponents of a "cognitive-historical approach" . I am thus concerned not just with refuting "the entering wedge" of the argument against a defense of cluster theory, but with offering a relatively developed theory, sufficiently fleshed out to permit appreciation of its distinctiveness and evaluation of its merits. ;I argue that the new cluster theory provides not only an adequate account of the process of meaning-making in science, but also a nuanced and context-sensitive one, which exhibits the fine-structure of the history of science. It is thus capable of accounting for the different kinds and degrees of meaning and reference changes in science. Furthermore, when applied in a case-study of the "chemical revolution," it accounts for that which has escaped change without discontinuity, or even, as result of a broader framework of continuous conceptual change. The new cluster theory constitutes a proposal showing how the comparability of scientific theories is possible, how we have in fact been comparing them all along, despite "local incommensurabilities" of various kinds and degrees. Such a theory offers new insights into the developments of the chemical revolution in particular, but also into the structure and process of scientific revolutions in general. In short, it gives us a new framework for understanding the rationality, objectivity, and progress of science. (shrink)

This is a qualitative study of the relationship between consonant cluster articulation and intelligibility in English as a Lingua Franca interactions in Japan. Some research has claimed that the full articulation of consonant clusters in lexeme-initial and lexeme-medial position is critical to the maintenance of intelligibility. Using conversation analytic methodology to examine a corpus of repair sequences in interactions among English as a Lingua Franca speakers at a Japanese university, this study claims that consonant elision in consonant clusters in (...) lexeme-initial, lexeme-medial, and lexeme-final position can attenuate intelligibility, and that the insertion of an elided consonant into a word that was oriented to as unintelligible can help restore intelligibility in English as a Lingua Franca. (shrink)

Traditional document clustering algorithms consider text-based features such as unique word count, concept count, etc. to cluster documents. Meanwhile, event mining is the extraction of specific events, their related sub-events, and the associated semantic relations from documents. This work discusses an approach to event mining through clustering. The Universal Networking Language -based subgraph, a semantic representation of the document, is used as the input for clustering. Our research focuses on exploring the use of three different feature sets for event (...) clustering and comparing the approaches used for specific event mining. In our previous work, the clustering algorithm used UNL-based event semantics to represent event context for clustering. However, this approach resulted in different events with similar semantics being clustered together. Hence, instead of considering only UNL event semantics, we considered assigning additional weights to similarity between event contexts with event-related attributes such as time, place, and persons. Although we get specific events in a single cluster, sub-events related to the specific events are not necessarily in a single cluster. Therefore, to improve our cluster efficiency, connective terms between two sentences and their representation as UNL subgraphs were also considered for similarity determination. By combining UNL semantics, event-specific arguments similarity, and connective term concepts between sentences, we were able to obtain clusters for specific events and their sub-events. We have used 112 000 Tamil documents from the Forum for Information Retrieval Evaluation data corpus and achieved good results. We have also compared our approach with the previous state-of-the-art approach for Router-RCV1 corpus and achieved 30% improvements in precision. (shrink)

Our prominent definitions of cognition are too vague and lack empirical grounding. They have not kept up with recent developments, and cannot bear the weight placed on them across many different debates. I here articulate and defend a more adequate theory. On this theory, behaviors under the control of cognition tend to display a cluster of characteristic properties, a cluster which tends to be absent from behaviors produced by non-cognitive processes. This cluster is reverse-engineered from the empirical (...) tests that comparative psychologists use to determine whether a behavior was generated by a cognitive or a non-cognitive process. Cognition should be understood as the natural kind of psychological process that non-accidentally exhibits the properties assessed by these tests (as well as others we have not yet discovered). Finally, I review two plausible neural accounts of cognition's underlying mechanisms?one based in localization of function to particular brain regions and another based in the more recent distributed networks approach to neuroscience?which would explain why these properties non-accidentally cluster. While this notion of cognition may be useful for a number of debates, I here focus on its application to a recent crisis over the distinction between cognition and association in comparative psychology. (shrink)

Clustering is one of the most fundamental and essential data analysis tasks with broad applications. It has been studied in various research fields: data mining, machine learning, pattern recognition and in engineering, economics and biomedical data analysis. Headache is not a disease that typically shortens one’s life, but it can be a serious social as well as a health problem. Approximately 27 billion euros per year are lost through reduced work productivity in the European community. This paper is focused on (...) a new strategy based on a hybrid model for combining fuzzy partition method and maximum likelihood estimation clustering algorithm for diagnosing primary headache disorder. The proposed hybrid system is tested on two data sets for diagnosing headache disorder collected from Clinical Centre of Vojvodina in Serbia. (shrink)

I argue that the many worlds explanation of quantum computation is not licensed by, and in fact is conceptually inferior to, the many worlds interpretation of quantum mechanics from which it is derived. I argue that the many worlds explanation of quantum computation is incompatible with the recently developed cluster state model of quantum computation. Based on these considerations I conclude that we should reject the many worlds explanation of quantum computation.

The type of research known as cluster randomized trials raises ethical questions not readily answered within the standard understanding of research ethics. What distinguishes a CRT is that it randomizes at the level of social groups rather than at the level of individual research participants: in a CRT, the regimen under study might be assigned to a village, hospital, or school. The organizational schemes of CRTs raise an assortment of fundamental ethical problems. In certain CRTs, the question of whether (...) it is possible to obtain individual informed consent is central. Also, if the intervention is offered at the level of a sizable social group, there is usually no realistic possibility for individuals to opt out of the trial. Other ethical questions raised by CRTs have to do with identifying the subjects of research, and indeed with whether “research” is occurring at all. (shrink)