Neural networks have frequently been found to give accurate solutions to hard classification problems. However neural networks do not make explained classifications because the class boundaries are implicitly defined by the network weights, and these weights do not lend themselves to simple analysis. Explanation is desirable because it gives problem insight both to the designer and to the user of the classifier. Many methods have been suggested for explaining the classification given by a neural network, but they all suffer from one or more of the following disadvantages: a lack of equivalence between the network and the explanation; the absence of a probability framework required to express the uncertainty present in the data; a restriction to problems with binary or coarsely discretised features; reliance on axis-aligned rules, which are intrinsically poor at describing the boundaries generated by neural networks. The structure of the solution presented in this thesis rests on the following steps: Train a standard neural network to estimate the class conditional probabilities. Bayes’ rule then defines the optimal class boundaries. Obtain an explicit representation of these class boundaries using a piece-wise linearisation technique. Note that the class boundaries are otherwise only implicitly defined by the network weights. Obtain a safe but possibly partial description of this explicit representation using rules based upon the city-block distance to a prototype pattern. The methods required to achieve the last two represent novel work which seeks to explain the answers given by a proven neural network solution to the classification problem.

Supplementary food is less variable than natural food. While feeding from constant food sources tends to be preferred by animals they must sometimes forage from more variable resources. However, the ways in which animals deal with the temporal and spatial variability of more natural food is not entirely understood. I investigated the decisions free-living rufous hummingbirds made when foraging from variable resources, where variability was encountered over time or within a bout via four field experiments. In addition, I investigated their use of wild flowers and differences in the use of supplementary food by these birds in different regions using surveys and by manipulating the distribution of feeders at feeding sites. I investigated the possibility of a genetic explanation for any differences in feeder use between regions using analysis of microsatellite DNA and banding data. Hummingbirds seemed to prefer to make foraging decisions based on past behaviour or post-ingestive feedback rather than on sensory information such as taste, which may be harder to assess accurately. Birds choosing between constant and variable rewards with equal means preferred the constant rewards when variability was high but tended to prefer the variable reward when variability was low. This seems to be a result of hidden time and other costs associated with foraging on highly variable resource but not on less variable ones, combined with potential benefits of information seeking from less variable resources. In addition, these preferences between constant and variable resources were affected by preceding foraging conditions. The number of birds using feeders was affected by population density and air temperature. Microsatellite data showed the rufous hummingbird population to have a fairly panmictic population structure. Investigating influences on foraging decisions at a large scale (population density) and small scale (resource variability) has provided a much wider understanding of their foraging behaviour than either could alone.

Systematic reviews of diagnostic test accuracy (DTA) studies are fundamental to the decision-making process in evidence-based medicine. Although such studies are regarded as high-level evidence, these reviews are not always reported completely and transparently. Sub-optimal reporting of DTA systematic reviews compromises their validity, generalizability, and value to key stakeholders. This thesis evaluates the completeness of reporting of published DTA systematic reviews based on the PRISMA-DTA checklist and provides an explanation for the new and modified items (relative to PRISMA), along with their meaning and rationale. Our results demonstrate that recently published reports of DTA systematic reviews are not fully informative, when evaluated against the PRISMA-DTA guidelines: mean reported items=18.6/26(71%, SD=1.9) for PRISMA-DTA; 5.5/11(50%, SD=1.2) for PRISMA-DTA for abstracts. The PRISMA-DTA statement, this document, and the associated website (http://www. prisma-statement.org/Extensions/DTA) are meant to be helpful resources to support the transparent reporting of DTA systematic reviews and guide knowledge translation strategies.

"Might makes right," so the saying goes. What does this mean? What does it mean to say that humans live by this saying? How can this saying that is considered by almost all as an expression of injustice play a justificatory role practically universally and ubiquitously? How can it be repulsive and yet, nonetheless, attractive as an explanation of the ways of the world? Why its long history? I offer a non-cynical explanation, one based on a re-interpretation of the saying and of both recognized and unrecognized related phenomena. This re-interpretation relies on the notion of a tacit justification for violence. This non-cynical, re-interpretive explanation exposes the ambiguity of the saying and the consequential unwitting, self-deceptive, fallacious equivocations that the ambiguity makes possible under common conditions. While this explanation, furthermore, focuses on thinking factors--specifically on fallacious thinking, on humans' unwittingly and self-deceptively committing the fallacy of equivocation--it does not deny the possible role of non-thinking factors; it only tries to show that the thinking factors are significantly explanatory. What is the ambiguity? "Might makes right" expresses two principles. The first principle is the common meaning, namely, that the dominance of the mightier over the weaker is right. This principle is generally considered to be not a definition of justice but an expression of injustice. The second principle, which is almost universally shared in a tacit and unreflective way, is a principle of life, namely, that it is right for any living being to actualize its potential. This second principle is originary and thus primary, while the first principle is derivative and thus secondary. The use of all powers, natural or social, can be ultimately derived legitimately or illegitimately from this primary principle. A common manifestation of "might makes right" is the unwitting abuse of power, an abuse that is not recognized as such by the so-called abuser, but that is rather suffered by this latter, who misapplies the second principle in situations that fall under the first principle, thereby unwittingly living by the saying, tacitly justifying abusive ways by it. This unwittingness calls for critical control and forgiveness.

Autores neopiagetianos como, por exemplo, Stambak et al. (1990), Verba (1999), Gardner (1994), Flavell (1999), Astington (2003) não têm medido esforços para mostrar o percurso e a importância do jogo simbólico para o desenvolvimento integral da criança. Nesta linha de raciocínio, o presente trabalho enfatiza o papel do jogo de ficção (Stambak et al. e Verba) nas produções discursivas infantis (Veneziano e Hudelot, 2002), reiterando a tese da força motriz do imaginário no e para o desenvolvimento da linguagem na criança. Considerando, portanto, que é pela manifestação de suas ações, sentimentos e emoções que o indivíduo atua sobre o outro, estamos admitindo que a linguagem assume um papel de destaque no processo de comunicação, pois garante diferentes operações intelectuais, e possibilita a criação de mundos e, conseqüentemente, de perspectivas. É ainda por meio da linguagem que o pensamento se organiza, que a criança se identifica como pessoa, argumenta, explica e/ou justifica, quando interage com o meio em que vive. Logo, seu estudo não pode estar desvinculado de suas condições de produção. Com este propósito, e no quadro de uma abordagem funcional e interacional, observamos as condutas explicativas e justificativas (CEJs), que aparecem durante o jogo de ficção com fantoches, onde os espectadores da animação são a própria criança, o boneco e o adulto, na construção do imaginário, na prática do “querer-fazer" e do “fazer-fazer". Assim, os resultados apontam para um número significativo de CEJs motivado pela linguagem e pelo prazer lúdico. O real e o imaginário aliam-se e criam um cenário onde a criança conquista, forma e domina novos territórios, promovendo o seu crescimento individual e coletivo. / Authors as Stambak et al. (1990), Verba (1999), Gardner (1994), Flavell (1999), Astington (2003) they have not been measuring efforts to show the course and the importance of the symbolic game for integral child development. For this reason, the present work emphasizes the paper of the fiction game (Stambak et al. and Verba) in the child discursive productions (Veneziano and Hudelot, 2002), reiterating the thesis of the imaginary force for the language development. Considering it is for the manifestation of actions, feelings and emotions that the person acts to the other, we are admitting that the language assumes a prominence paper in the communication process because it guarantees different intellectual operations, and it makes possible the creation of worlds and consequently perspectives. It is still through the language that the thought is organized, that the child identifies as person, she argues, she explains and/or she justifies, when she interacts with the environment she lives. Therefore, the investigation cannot be disentailed of the production conditions. With this purpose, and in the picture of a functional approach and interacional, we observed the explanation and justification conducts (EJCs), that appear during the fiction game with puppets, where the spectators of the animation are the own child, the puppet and the adult in the imaginary construction. The results appear for a significant number of EJCs motivate by the language and by the pleasure to play. The real and the imaginary ally and they create a scenery where the child conquers, she forms and she dominates new territories and she promote her individual and collective growth.

Partindo da idéia de que não há oposição fundamental entre explicação e narração, pois ao contar uma história explicamos e, ao explicar, legitimamos o caráter memorável daquilo que contamos, elegemos como objeto de estudo a relação entre compreensão e produção de histórias orais em seis crianças, de cinco anos, de ambos os sexos, observando o papel da avaliação (Labov, 1972), bem como para identificar a articulação dos processos narrativo/explicativo presentes nas produções infantis. Para tanto, propomos uma análise de narrativa, a partir do modelo apresentado por Labov, mas procedendo de modo diferente do autor, uma vez que ele se ocupou das narrativas de experiências pessoais, onde os locutores se preocupam em reconstruir, até em reviver fatos de seu passado. Nesta perspectiva, adaptamos este modelo de narrativa com o olhar voltado para as histórias orais elaboradas pelas crianças. De acordo com o autor, a avaliação é um dos elementos estruturais da narrativa que tem por finalidade comunicar ao ouvinte o ponto de vista do narrador em relação à história por ele narrada, ou seja, a função avaliativa diz respeito à necessidade que tem o locutor de manter o interesse do interlocutor durante a narração. Considerando que é nosso objetivo estabelecer uma relação entre o narrar e o explicar com base no procedimento da avaliação (Labov), nos apoiamos em alguns autores (Hudelot et al. Veneziano, Halté entre outros) que tratam da explicação. Segundo Hudelot et al. (2003), o termo 'explicação' remete a um universo de sentidos, pois para explicar o significado de uma palavra ou de uma ação, é necessário analisar o contexto e o sentido da mesma, de modo que seja possível torná-la inteligível para o interlocutor. Leclaire-Halté (1990) afirma que a explicação, em textos de ficção, surge quando há um problema que deve ser resolvido. Assim, observamos e contrastamos duas situações: (a) produção de histórias orais a partir de desenhos feitos pelas crianças; e (b) a produção de narrativas a partir das histórias lidas pela pesquisadora, apoiando-nos para isso em autores que tratam tanto da comunicação verbal, como da comunicação não-verbal. As conclusões confirmam que, embora as histórias elaboradas nas duas situações apresentem características distintas da linguagem oral e escrita, ambas mantêm em comum a articulação do explicar e do narrar. / From the idea that there is no fundamental opposition between explanation and narration, because when one tells a story one explains it and explaining we legitimize the memorable character of what we tell, we’ve elected as the object of our study, the comprehension and production of oral stories in six children of five years old, of both genders, observing the role of the evaluation (Labov,1972) as well as to identify the articulation of narrative/explicative processes present in the children’s production. For that, we propose an analysis of the narrative starting from the model presented by Labov, but proceeding in a different way from that of author once he’s been dealing with the narratives of personal experience in which the locutor are worried about reconstructing or even reliving facts of their past. In this perspective, we’ve adapted this model of narrative looking at the oral stories produced by the children. According to the author, the evaluation is one of the structural elements of the narrative which has as its aim communicate to the listener the point of view of the narrator in relation to the story narrated by him, in other words, the evaluative function is concerned about the necessity that the locutor has of keeping the interest of the interlocutor along the narration. Considering that it’s our objective to establish a relation between the narrating and explaining based on the procedure of evaluation (Labov), we’ve found support in some authors (Hudelot et al., Veneziano, Halté among others) that work with explanation. According to Hudelot et al. (2003), the term 'explanation' refer a universe of senses, that is to explain the meaning of a word or action it’s necessary to analyses its context and sense that it’s possible to make the word or action intelligible to the interlocutor. Leclaire-Halté (1990) states that the explanation in fiction texts, arises when there is a problem that must be solved. This way, we’ve observed and contrasted two situations: (a) production of oral stories through drawings done by the children; and (b) the production of narratives through the stories read by the researcher being supported by authors that deal with both the verbal communication and the non-verbal communication. The conclusions confirm that although the produced stories in both situations present distinct characteristics of oral and written language, both keep the articulation of explaining and narrating in common.

The epistemological problem of the external world asks: (1) “How is knowledge of the world possible given certain obstacles which make it look impossible?” This is a “how-possible?” question: it asks how something is possible given certain obstacles which make it look impossible (cf. Cassam 2007; Nozick 1981; Stroud 1984). Now consider the following question, which asks: (2) “How is a philosophically satisfying answer to (1) possible?” Scepticism is the thesis that knowledge of the world is impossible. It therefore represents a negative answer to the first question. Meta-epistemological scepticism is the thesis that a satisfying philosophical explanation of how our knowledge of the world is possible is itself not possible. It therefore represents a negative answer to the second question. In this thesis, I explore the prospects of meta-epistemological scepticism. In particular, I structure the thesis around two master arguments from Stroud (1984, 2000, 2004, and 2009) for meta-epistemological scepticism. The first argument is what I call “Stroud’s puzzle”, and the second argument is “Stroud’s dilemma” (cf. Cassam 2009). I argue that Stroud’s puzzle fails to provide adequate support for meta-epistemological scepticism. However, I also argue that Stroud’s dilemma withstands serious objections (e.g., from Sosa 1994, Williams 1996, and Cassam 2009). In short, while Stroud’s puzzle fails to provide adequate support for meta-epistemological scepticism, Stroud’s dilemma does seem to provide adequate support for meta-epistemological scepticism. This thesis therefore represents a partial defence of meta-epistemological scepticism. Meta-epistemological scepticism is therefore a live option in epistemology. In Chapter 1, I explain what meta-epistemological is, present Stroud’s puzzle and Stroud’s dilemma for meta-epistemological scepticism, and argue that meta-epistemological sceptics are not committed to first-order scepticism. In Chapter 2, I examine what I call the “anti-revisionist” premise of Stroud’s puzzle and argue that it lacks adequate support. In Chapter 3, I examine the “conditional scepticism” premise of Stroud’s puzzle and argue that it lacks adequate support. In Chapter 4, I look at Williams’s (1996) master argument against Stroud’s dilemma, and argue that it fails. In Chapter 5, I look at externalist responses to Stroud’s dilemma, and in particular, Sosa (1994). I argue that Sosa’s objection fails, and therefore Stroud’s dilemma survives serious externalist objections. In Chapter 6, I explain Cassam’s (2009) argument against Stroud’s dilemma, and I argue that it fails. Chapter 7 concludes the thesis, summarising the main results.

The topics of Grounding and Metaphysical Explanation have been at the forefront of research and debate within metaphysics for the last decade. Grounding is commonly taken to be a relation of non-causal dependence. In this thesis I address the pertinent question as to what sorts of entities are related in instances of grounding. There has so far been little enquiry into this issue, and it therefore requires urgent attention. I argue here that the entities involved in grounding are facts, where facts are true Fregean propositions. True Fregean propositions are abstract entities composed of senses, and are individuated according the senses which they involve. I proceed by setting out some desiderata which the entities involved in grounding will fulfil. Firstly, they will be individuated sufficiently finely as to provide instances of grounding to back all putative cases of non-causal explanation. Secondly, they will ensure that there is unity between instances of grounding and instances of causation. Finally, they will be mind- independent. I survey different types of entity and show that true Fregean propositions are best-equipped to fulfil these desiderata. We therefore have reason to believe that grounding relates facts, so understood. The conclusion of this thesis therefore makes it incumbent upon us to extend our ontology to include true Fregean propositions.

Partindo da idéia de que não há oposição fundamental entre explicação e narração, pois ao contar uma história explicamos e, ao explicar, legitimamos o caráter memorável daquilo que contamos, elegemos como objeto de estudo a relação entre compreensão e produção de histórias orais em seis crianças, de cinco anos, de ambos os sexos, observando o papel da avaliação (Labov, 1972), bem como para identificar a articulação dos processos narrativo/explicativo presentes nas produções infantis. Para tanto, propomos uma análise de narrativa, a partir do modelo apresentado por Labov, mas procedendo de modo diferente do autor, uma vez que ele se ocupou das narrativas de experiências pessoais, onde os locutores se preocupam em reconstruir, até em reviver fatos de seu passado. Nesta perspectiva, adaptamos este modelo de narrativa com o olhar voltado para as histórias orais elaboradas pelas crianças. De acordo com o autor, a avaliação é um dos elementos estruturais da narrativa que tem por finalidade comunicar ao ouvinte o ponto de vista do narrador em relação à história por ele narrada, ou seja, a função avaliativa diz respeito à necessidade que tem o locutor de manter o interesse do interlocutor durante a narração. Considerando que é nosso objetivo estabelecer uma relação entre o narrar e o explicar com base no procedimento da avaliação (Labov), nos apoiamos em alguns autores (Hudelot et al. Veneziano, Halté entre outros) que tratam da explicação. Segundo Hudelot et al. (2003), o termo 'explicação' remete a um universo de sentidos, pois para explicar o significado de uma palavra ou de uma ação, é necessário analisar o contexto e o sentido da mesma, de modo que seja possível torná-la inteligível para o interlocutor. Leclaire-Halté (1990) afirma que a explicação, em textos de ficção, surge quando há um problema que deve ser resolvido. Assim, observamos e contrastamos duas situações: (a) produção de histórias orais a partir de desenhos feitos pelas crianças; e (b) a produção de narrativas a partir das histórias lidas pela pesquisadora, apoiando-nos para isso em autores que tratam tanto da comunicação verbal, como da comunicação não-verbal. As conclusões confirmam que, embora as histórias elaboradas nas duas situações apresentem características distintas da linguagem oral e escrita, ambas mantêm em comum a articulação do explicar e do narrar. / From the idea that there is no fundamental opposition between explanation and narration, because when one tells a story one explains it and explaining we legitimize the memorable character of what we tell, we’ve elected as the object of our study, the comprehension and production of oral stories in six children of five years old, of both genders, observing the role of the evaluation (Labov,1972) as well as to identify the articulation of narrative/explicative processes present in the children’s production. For that, we propose an analysis of the narrative starting from the model presented by Labov, but proceeding in a different way from that of author once he’s been dealing with the narratives of personal experience in which the locutor are worried about reconstructing or even reliving facts of their past. In this perspective, we’ve adapted this model of narrative looking at the oral stories produced by the children. According to the author, the evaluation is one of the structural elements of the narrative which has as its aim communicate to the listener the point of view of the narrator in relation to the story narrated by him, in other words, the evaluative function is concerned about the necessity that the locutor has of keeping the interest of the interlocutor along the narration. Considering that it’s our objective to establish a relation between the narrating and explaining based on the procedure of evaluation (Labov), we’ve found support in some authors (Hudelot et al., Veneziano, Halté among others) that work with explanation. According to Hudelot et al. (2003), the term 'explanation' refer a universe of senses, that is to explain the meaning of a word or action it’s necessary to analyses its context and sense that it’s possible to make the word or action intelligible to the interlocutor. Leclaire-Halté (1990) states that the explanation in fiction texts, arises when there is a problem that must be solved. This way, we’ve observed and contrasted two situations: (a) production of oral stories through drawings done by the children; and (b) the production of narratives through the stories read by the researcher being supported by authors that deal with both the verbal communication and the non-verbal communication. The conclusions confirm that although the produced stories in both situations present distinct characteristics of oral and written language, both keep the articulation of explaining and narrating in common.

In this dissertation I consider the problem of external world skepticism and attempts at providing an argument to the best explanation against it. In chapter one I consider several different ways of formulating the crucial skeptical argument, settling on an argument that centers on the question of whether we're justified in believing propositions about the external world. I then consider and reject several options for getting around this issue which I take to be inadequate. I finally conclude that the best option available to us at the moment is to argue that the antiskeptical view is the best explanation of our ordinary experiences In chapter two I argue that, if we hope to ground what counts as defending antiskepticism in common sense, there is an argument against the possibility of ever knowing one has succeeded in defending antiskepticism. After showing that common sense is no place to look in setting a goal for our antiskeptical project, I present the view that what will be crucial to settling on our antiskeptical goal is coming to a successful analysis of the nature of physical objects. I suggest some minimal criteria that must be met by a view in order to be antiskeptical based on our intuitions about core skeptical cases, but acknowledge that a fully successful response to external world skepticism will require the antiskeptic to engage in some much more difficult analysis. In chapter three I consider various views of the nature of explanation and conclude, tentatively, that explanation as it interests the antiskeptic is fundamentally causal. In chapter four I consider and reject some of the core views on which best explanation facts are so fundamental that a project of attempting to vindicate probabilistically the virtues which make explanations epistemically good. In this chapter I show that views which analyze justification in terms of best explanation factors fail. In chapter five I attempt to vindicate the various explanatory virtues probabilistically. In doing so I attempt to express or translate the various explanatory virtues in terms of probabilities in order to show that having those virtues makes a view at least prima facie more probable. In chapters six and seven I explain and evaluate the various arguments to the best explanation against skepticism present in current philosophical literature. I attempt to show that extant arguments fail to appreciate the virtues possessed by classical (and some new) skeptical scenarios. In chapter eight I briefly consider some options that may be open to the antiskeptic moving forward. All routes forward contain considerable obstacles, but there are some fruitful areas of research to pursue.