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The ability to change one's beliefs in a rational manner is one of many facets of the abilities of an intelligent agent. Central to any investigation of belief change is the notion of an epistemic state. This dissertation is mainly concerned with three issues involving epistemic states: 1. How should an epistemic state be represented? 2. How does an agent use an epistemic state to perform belief change? 3. How does an agent arrive at a particular epistemic state? With regard to the first question, note that there are many different methods for constructing belief change operations. We argue that semantic constructions involving ordered pairs, each consisting of a set of beliefs and an ordering on the set of "possible worlds" (or equivalently, on the set of basic independent bits of information) are, in an important sense, more fundamental. Our answer to the second question provides indirect support for the use of semantic structures. We show how well-known belief change operations and related structures can be modelled semantically. Furthermore, we introduce new forms of belief change related operations and structures which are all defined, and motivated, in terms of such semantic representational formalisms. These include a framework for unifying belief revision and nonmonotonic reasoning, new versions of entrenchment orderings on beliefs, novel approaches to withdrawal operations, and an expanded view of iterated belief change. The third question is. one which has not received much attention in the belief change literature. We propose to extract extra-logical information from the formal representation of an agent's set of beliefs, which can then be used in the construction of epistemic state. his proposal is just a first approximation, although it seems to have the potential for developing into a full-fledged theory. / Computing / D.Phil.(Computer Science)

The ability to change one's beliefs in a rational manner is one of many facets of the abilities of an intelligent agent. Central to any investigation of belief change is the notion of an epistemic state. This dissertation is mainly concerned with three issues involving epistemic states: 1. How should an epistemic state be represented? 2. How does an agent use an epistemic state to perform belief change? 3. How does an agent arrive at a particular epistemic state? With regard to the first question, note that there are many different methods for constructing belief change operations. We argue that semantic constructions involving ordered pairs, each consisting of a set of beliefs and an ordering on the set of "possible worlds" (or equivalently, on the set of basic independent bits of information) are, in an important sense, more fundamental. Our answer to the second question provides indirect support for the use of semantic structures. We show how well-known belief change operations and related structures can be modelled semantically. Furthermore, we introduce new forms of belief change related operations and structures which are all defined, and motivated, in terms of such semantic representational formalisms. These include a framework for unifying belief revision and nonmonotonic reasoning, new versions of entrenchment orderings on beliefs, novel approaches to withdrawal operations, and an expanded view of iterated belief change. The third question is. one which has not received much attention in the belief change literature. We propose to extract extra-logical information from the formal representation of an agent's set of beliefs, which can then be used in the construction of epistemic state. his proposal is just a first approximation, although it seems to have the potential for developing into a full-fledged theory. / Computing / D.Phil.(Computer Science)

Dans les logiques épistémiques, la connaissance est généralement modélisée par un graphe de mondes possibles, qui correspondent aux alternatives à l'état actuel du monde. Ainsi, les arêtes entre les mondes représentent l'indistinguabilité. Connaître une proposition signifie que cette proposition est vraie dans toutes les alternatives possibles. Les informaticiens théoriques ont cependant remarqué que cela a conduit à plusieurs problèmes, à la fois intuitifs et techniques : plus un agent est ignorant, plus elle a d'alternatives à examiner ; les modèles peuvent alors devenir trop grands pour la vérification de système. Ils ont récemment étudié comment la connaissance pourrait être réduite à la notion de visibilité. Intuitivement, l'idée de base est que quand un agent voit quelque chose, alors elle sait sa valeur de vérité. A l'inverse, toute combinaison de valeurs de vérité des variables non observables est possible pour l'agent. Ces informations d'observabilité permettent de reconstituer la sémantique standard de la connaissance : deux mondes sont indistinguables pour un agent si et seulement si chaque variable observée par cet agent a la même valeur dans les deux mondes. Notre objectif est de démontrer que les logiques épistémiques fondées sur la visibilité constituent un outil approprié pour plusieurs applications importantes dans le domaine de l'intelligence artificielle. Dans le cadre actuel de ces logiques de visibilité, chaque agent a un ensemble de variables propositionnelles qu'elle peut observer ; ces visibilités sont constantes à travers le modèle. Cela accompagne une hypothèse forte : les visibilités sont connues de tous, et sont même connaissance commune. De plus, la construction de la connaissance à partir de la visibilité entraîne des validités contre-intuitives, la plus importante étant que l'opérateur de la connaissance distribue sur les disjonctions de littéraux : si un agent sait que p ou q est vrai, alors elle sait que p est vrai ou que q est vrai, parce qu'elle peut les voir. Dans cette thèse, nous proposons des solutions à ces deux problèmes et les illustrons sur diverses applications telles que la planification épistémique ou les jeux booléens épistémiques, et sur des exemples plus spécifiques tels que le problème des enfants sales ou le problème du bavardage. Nous étudions en outre des propriétés formelles des logiques que nous concevons, fournissant axiomatisations et résultats de complexité. / In epistemic logic, knowledge is usually modelled by a graph of possible worlds, representing the alternatives to the current state of the world. So edges between worlds stand for indistinguishability. To know a proposition means that that proposition is true in all possible alternatives. Theoretical computer scientists however noticed that this led to several issues, both intuitively and technically: the more an agent is ignorant, the more alternatives she must consider; models may then become too big for system verification. They recently investigated how knowledge could be reduced to the notion of visibility. Intuitively, the basic idea is that when an agent sees something, then she knows its truth value. The other way round, any combination of truth values of the non-observable variables is possible for the agent. Such observability information allows us to reconstruct the standard semantics of knowledge: two worlds are indistinguishable for an agent if and only if every variable observed by her has the same value in both worlds. We aim to demonstrate that visibility-based epistemic logics provide a suitable tool for several important applications in the field of artificial intelligence. In the current settings of these logics of visibility, every agent has a set of propositional variables that she can observe; these visibilities are constant across the model. This comes with a strong assumption: visibilities are known to everyone, and are even common knowledge. Moreover, constructing knowledge from visibility brings about counter-intuitive validities, the most important being that the knowledge operator distributes over disjunction of literals: if an agent knows that p or q is true, then she knows that p is true or that q is true because she can see them. In this thesis, we propose solutions to these two problems and illustrate them on various applications such as epistemic planning or epistemic boolean games, and on more specific examples such as the muddy children problem or the gossip problem. We moreover study formal properties of the logics we design, providing axiomatizations and complexity results.

The quest for epistemic liberation remains an important project in the post-colonial era of Zambia, and entails challenging the existing inequalities in knowledge representation at the epistemic front in the country. At the core of this quest is the position that the continued dominance of Western knowledge and the corresponding marginalisation of indigenous knowledges amount to an epistemic injustice that affects the contemporary existence of the peoples in the country. This study critically examines the problem of epistemic injustice in Zambia while reflecting on the country’s uncompleted project of decolonisation. It traces the problem from the theoretical assumption of modernity that Western knowledge is universal and that it should, therefore, be applied to all societies in the world. It is submitted that the current education system in Zambia is based on this assumption, and, consequently, favours Western knowledge to the exclusion of indigenous knowledges. This practice is identified as a conduit for accelerating epistemic injustice and its intensity in the country. The study approaches this problem from an African philosophical standpoint, and draws its current from the history of the political struggle against domination on the continent. To adequately confront the problem of epistemic injustice in Zambia, the study suggests parity and equilibrium in representation between indigenous knowledges and Western knowledge in the country. / Philosophy, Practical and Systematic Theology / M.A. (Philosophy)

No description available.

This dissertation investigates the expression of the indirect evidential subdomain in two languages in contact, i.e. the northern variety of Central Aymara and the variety of Spanish spoken in La Paz (Bolivia). For this aim, the study uses first-hand data collected in La Paz and El Alto (Bolivia) during 2014 and 2015. Data was elicited through: the “Family Problems Picture” task (San Roque et al. 2012), formulated by the members of the Max Planck Institute for Psycholinguistics and created specifically for the activation of cognitive categories such as evidentiality and mirativity; the “Pear Story” designed for Wallace Chafe, professor at the University of California, to collect narrative texts that show how humans perceive, elaborate and verbalize experience; and, finally, personal narratives, traditional narratives and interviews. Thirty-three recordings (12h 48’) of 48 Spanish-Aymara bilingual speakers (17 males, age range: 18-64) were fully transcribed and annotated. The resulting corpus consists of 33 transcriptions of which 14 are in Aymara (c. 19 154 words), whereas 19 are in Spanish (c. 46 245 words). The dissertation is built around four research questions. First, the dissertation shows the functions of the forms identified in the data in both languages. The study identifies for each form both evidential and non-evidential functions. Indirect evidential functions are systematically analyzed and classified by combining Willett’s (1988) and Aikhnvald’s (2004) classifications. The analysis shows evidential functions of forms that have not been previously studied as such, i.e. digamos and diciendo in Spanish and sañani and sapxi in Aymara, but it also reveals unnoticed evidential functions for previously described forms. Second, the dissertation provides a clear view of the relationship between the evidential and the epistemic modal domain involved in the use of the forms identified. Two types of correlation are found. Both languages, indeed, show forms that only point out the way in which speakers acquired information and forms where the two domains overlap. Third, the dissertation investigates speakers’ epistemic stance, in terms of commitment, towards information involved in the use of the evidential forms identified. The study shows that the forms which convey merely evidential information express mainly a medium-high commitment degree, whereas the forms in which the distinction between the evidential and the epistemic modal domain is blurred indicate a low degree of commitment. Forth, the dissertation sheds light on the relationship between the expressions of the indirect evidential subdomain in the two languages. The study proposes a quantitative and qualitative analysis of the evidential types and subtypes in both languages. The results show a high degree of convergence between the two languages, suggesting also situations of influence of one language on the other.

This thesis examines some epistemic defences of democracy put forward by David Estlund, Michael Fuerstein, Cheryl Misak, and Fabienne Peter, as well as a critique of democracy raised by Jason Brennan. It then develops an epistemic defence of a moderately non-egalitarian system, which it proposes to call liberal trusteeship. According to the proposed theory, the power to draft laws ought to be separated from the power to enact those drafts into law. The former power ought to be vested in trustees, who are essentially specialists that have inquired extensively into a given matter, and the latter power ought to be vested in a democratically elected parliament. Subsequently, this thesis argues that parliament should nevertheless have the prerogative to ultimately override trustees on ethics and pass its own legislation regulating moral matters; that the criteria for selecting trustees should be determined by jury courts; and that parliament and jury courts should be given some powers to influence the composition of trustee committees, so that the political process can guard against the risk that trustees might be biased or corrupt. The above proposal is grounded on three principal claims. Firstly, this thesis argues that moral authority and legitimacy ought to be reserved for the political system that strikes the best balance between competence and equality. Secondly, it argues that liberal trusteeship is more likely than democracy to determine correctly what ought to be done in light of the progress of open and vigorous inquiry into a given matter. Thirdly, and as a result, it argues that liberal trusteeship is likely to exercise power sufficiently more competently than democracy, such that its moderate deviation from political equality will be justified. In the light of this, the thesis concludes that liberal trusteeship would strike a better balance between competence and equality than democracy.

Die Förderung epistemischer Überzeugungen gilt als wichtige Aufgabe in der Lehrerbildung. Insbesondere im bildungswissenschaftlichen Begleitstudium tendieren Studierende jedoch zu ungünstigen Überzeugungen: Bildungswissenschaftliches Wissen wird im Vergleich zu fachwissenschaftlichem Wissen als wenig systematisiert, subjektiv und kaum praxisrelevant beurteilt. Wie Studierende dabei unterstützt werden können, angemessene Überzeugungen zum Wissen in den Bildungswissenschaften zu entwickeln, ist empirisch noch unzureichend untersucht. Aus diesem Grund wurden literaturgestützt drei Kurzinterventionen entwickelt, die auf je spezifischen Förderstrategien gründen: (1) Direkt-explizite Adressierung von epistemischen Überzeugungen, (2) indirekt-implizite Adressierung und (3) Kombination aus direkten und indirekten Förderansätzen. Die Eignung der drei Interventionen wurde in einem quasi-experimentellen Mixed-Methods-Design in zwei Teilstudien untersucht. Die quantitative Teilstudie umfasste eine Veränderungsmessung. Es konnte gezeigt werden, dass sich die Studierenden aus der direkten und der kombinierten Intervention tendenziell in Richtung reflektierter Überzeugungen weiterentwickelt haben. Die indirekte Intervention blieb dagegen wirkungslos. Die qualitative Teilstudie umfasste die Analyse von Follow-Up-Interviews, die im Nachgang der Interventionen mit teilnehmenden Studierenden geführt wurden. Die Ergebnisse stützten erstens die Befunde aus der quantitativen Teilstudie, wobei ein besonderes Veränderungspotenzial für die kombinierte Intervention deutlich wurde. Zweitens konnten die zugrunde liegenden Wirkweisen der verschiedenen Interventionen herausgearbeitet werden. Drittens konnten weiterführende Erkenntnisse zu den grundlegenden Veränderungsmechanismen epistemischer Überzeugungen erzielt werden. Das bestehende Veränderungsmodell epistemischer Überzeugungen konnte weiterentwickelt und um individuelle Faktoren ergänzt werden. / Fostering epistemic beliefs is considered an important task in teacher education. However, especially in educational science, preservice teachers tend to hold unfavorable epistemic beliefs: Compared to knowledge in other disciplines, educational knowledge is perceived to be less systematic, subjective and irrelevant for classroom practice. However, how students can be supported in developing adequate beliefs about educational knowledge has not been sufficiently explored. For this reason, three short-term interventions were designed, each based on specific approaches to elicit changes in students’ epistemic beliefs (1) direct-explicit approach, (2) indirect-implicit approach, and (3) combination of direct and indirect approaches. The effectiveness of the three interventions was investigated in a quasi-experimental mixed-methods design in two studies. In the quantitative study a measurement of change was performed. It was shown that students from the direct and combined intervention groups tended to develop more adequate beliefs. The indirect intervention, in contrast, can be considered ineffective. The qualitative study involved the analysis of follow-up interviews conducted with participating students after the interventions. First, the results supported the findings from the quantitative study, highlighting a particular potential for change in the combined intervention. Second, the underlying ways in which the interventions stimulated change were identified. Third, further insights into the underlying mechanisms of epistemic change were obtained. The existing model of epistemic change was refined and complemented by individual factors that can influence the process of epistemic change.

Fehlende Kompetenzen in Mathematik und Naturwissenschaften werden von Studierenden als ein Grund für den Studienabbruch in Ingenieurwissenschaften angegeben (Heublein et al., 2017). Welche Kompetenzen für Studierende zu Beginn des Ingenieurstudiums relevant sind, ist jedoch bisher wenig empirisch untersucht. Das Ziel der vorliegenden Studie ist, relevante mathematische Kompetenzen von Ingenieurstudierenden zu analysieren und dabei sowohl Wissensbestände als auch die Anwendung von Wissen und die Zusammenhänge zwischen beiden Bereichen zu berücksichtigen. Dazu wurde eine Studie im Mixed-Methods Design entwickelt. In dieser werden die Studierenden hinsichtlich ihrer Dispositionen in Mathematik und Physik zu Beginn des Studiums und am Ende des ersten Studienjahres mit quantitativen Methoden getestet. Zu diesen beiden und einem weiteren Zeitpunkt am Ende des ersten Semesters wurden zudem die situationsspezifischen Fähigkeiten bei der Bearbeitung von Mathematik- und Physikaufgaben mit Hilfe eines theoretischen Rahmens zum mathematischen Problemlösen mit qualitativen Methoden untersucht. Dieser Theorierahmen umfasste für die Mathematikaufgaben die Aspekte Heurismen (Bruder & Collet, 2011; Schoenfeld, 1980) und Problemlösephasen (Polya, 1957) sowie das Modell der Epistemic Games (Tuminaro, 2004) zur Analyse der Bearbeitung von Physikaufgaben. Die Ergebnisse zeigen Zusammenhänge zwischen mathematischen und physikali-schen Dispositionen. Zusätzlich wird die Bedeutung von Aspekten des Problemlösens deutlich, um die Prozesse bei den Bearbeitungen von Mathematik und Physikaufgaben im ersten Studienjahr zu analysieren. Auf Grundlage der qualitativen Beschreibungen konnten Cluster von Fällen von Studierenden gebildet werden. Mit Hilfe dieser Cluster zeigen sich Zusammenhänge zwischen den Dispositionen und situationsspezifischen Fähigkeiten bei den besonders leistungsstarken und leistungsschwachen Studierenden. / Missing competences in mathematics and sciences are cited by students as a reason for the drop-out in engineering sciences (Heublein et al., 2017). However, the competences that are relevant for students at the beginning of their engineering studies have so far not been investigated in an empirical way. The aim of this study is to analyse relevant mathematical competences of engineering students, taking into account both knowledge and the application of knowledge and the interrelationships between the two. A study in mixed method design was developed for this purpose. In this study, students are tested with regard to their dispositions in mathematics and physics at the beginning of their studies and at the end of the first year of their studies using quantitative methods. At these two points in time and a further time at the end of the first semester, the situation-specific skills in processing math and physics tasks were examined with the help of a theoretical framework for solving mathematical problems, using qualitative methods. This theoretical framework included for the mathematical tasks the aspects heuristics (Bruder & Collet, 2011; Schoenfeld, 1980) and problem solving phases (Polya, 1957) as well as the model of Epistemic Games (Tuminaro, 2004) for the analysis of the processing of physical tasks. The results show interrelationships between mathematical and physical dispositions. In addition, it became clear that there is a need of problem solving aspects in order to analyse the processes involved in the working on maths and physics tasks in the first year of studies. Based on the qualitative descriptions, clusters of student cases could be formed. These clusters show the interrelationships between dispositions and situation-specific skills of particularly high-performing and underperforming students.