Heurísticas e inferencias causales en sistemas expertos

El objetivo de este trabajo es investigar desde una perspectiva epistemológica los aportes que pueda realizar la implementación de sistemas expertos en el ámbito de la diagnosis médica. En particular analizando el sistema experto Internist I. Dicho sistema es de interés para nuestro trabajo porque hace uso de las llamadas "redes bayesianas". El análisis de este sistema computacional permite indagar en cuestiones tales como: la modelización de una tarea compleja como la diagnosis médica, la relación entre los supuestos no "teóricos" del sistema computacional y su implementación concreta y la forma en la cual se reconstruye la discusión tradicional acerca de la distinción entre contextos de justificación y de descubrimiento. En relación con la modelización de la diagnosis, se puede señalar la relación existente sobre una distinción importante para la resolución de problemas entre problemas bien-estructurados y problemas por-estructurar.Fil: Huvelle, Xavier. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Escuela de Filosofía; Argentina.Filosofía, Historia y Filosofía de la Ciencia y la Tecnologí

Concrete causation

Concrete Causation beschäftigt sich mit Theorien der Verursachung, ihrer Interpretation und ihrer Einbettung in metaphysisch-ontologische Fragestellungen sowie der Anwendung solcher Theorien in naturwissenschaftlichem und entscheidungstheoretischem Kontext. Die Arbeit gliedert sich in vier Kapitel, die eine historisch-systematische Verortung der zentralen Probleme vornehmen (Kapitel 1), um dann eine begriffliche und technische Darstellung der Theorien von David Lewis und Judea Pearl zu liefern (Kapitel 2). Der mathematisch-technische Rahmen von Pearl (in Bayes'schen Netzen) wird nach philosophisch motivierten begrifflichen Überlegungen für eine epistemische Interpretation von Kausalität und in einer Erweiterung des interventionistischen Ansatzes für die Betonung des wissensordnenden Aspekts von Kausalrelationen herangezogen (Kapitel 3). Die Integration von kausalem und nicht-kausalem Wissen in einheitlichen Strukturen stellt einen Ansatz zur Lösung von Problemen der (kausalen) Entscheidungstheorie dar und ermöglicht gleichzeitig die Abbildung von logisch-mathematischen, synonymischen sowie reduktiven Zusammenhängen in operationalisierbaren Netzen der Belief Propagation (Kapitel 4).Concrete Causation centers about theories of causation, their interpretation, and their embedding in metaphysical-ontological questions, as well as the application of such theories in the context of science and decision theory. The dissertation is divided into four chapters, that firstly undertake the historical-systematic localization of central problems (chapter 1) to then give a rendition of the concepts and the formalisms underlying David Lewis' and Judea Pearl's theories (chapter 2). After philosophically motivated conceptual deliberations Pearl’s mathematical-technical framework is drawn on for an epistemic interpretation and for emphasizing the knowledge-organizing aspect of causality in an extension of the interventionist Bayes net account of causation (chapter 3). Integrating causal and non-causal knowledge in unified structures ultimately leads to an approach towards solving problems of (causal) decision theory and at the same time facilitates the representation of logical-mathematical, synonymical, as well as reductive relationships in efficiently structured, operational nets of belief propagation (chapter 4)

Causation and the Objectification of Agency

This dissertation defends the so-called 'agency-approach' to causation, which attempts to ground the causal relation in the cause's role of being a means to bring about its effect. The defence is confined to a conceptual interpretation of this theory, pertaining to the concept of causation as it appears in a causal judgement. However, causal judgements are not seen as limited to specific domains, and they are not exclusively attributed to human agents alone. As a methodological framework to describe the different perspectives of causal judgments, a method taken from the philosophy of information is made use of – the so-called 'method of abstraction'. According to this method, levels of abstraction are devised for the subjective perspective of the acting agent, for the agent as observer during the observation of other agents’ actions, and for the agent that judges efficient causation. As a further piece of propaedeutic work, a class of similar (yet not agency-centred) approaches to causation is considered, and their modelling paradigms – Bayesian networks and interventions objectively construed – will be criticised. The dissertation then proceeds to the defence of the agency-approach, the first part of which is a defence against the objection of conceptual circularity, which holds that agency analyses causation in causal terms. While the circularity-objection is rebutted, I rely at that stage on a set of subjective concepts, i.e. concepts that are eligible to the description of the agent’s own experience while performing actions. In order to give a further, positive corroboration of the agency-approach, an investigation into the natural origins and constraints of the concept of agency is made in the central chapter six of the dissertation. The thermodynamic account developed in that part affords a third-person perspective on actions, which has as its core element a cybernetic feedback cycle. At that point, the stage is set to analyse the relation between the first- and the third-person perspectives on actions previously assumed. A dual-aspect interpretation of the cybernetic-thermodynamic picture developed in chapter six will be directly applied to the levels of abstraction proposed earlier. The level of abstraction that underpins judgments of efficient causation, the kind of causation seemingly devoid of agency, will appear as a derived scheme produced by and dependent on the concept of agency. This account of efficient causation, the ‘objectification of agency’, affords the rebuttal of a second objection against the agency-approach, which claims that the approach is inappropriately anthropomorphic. The dissertation concludes with an account of single-case, or token level, causation, and with an examination of the impact of the causal concept on the validity of causal models