A structured argumentation framework for detaching conditional obligations

We present a general formal argumentation system for dealing with the detachment of conditional obligations. Given a set of facts, constraints, and conditional obligations, we answer the question whether an unconditional obligation is detachable by considering reasons for and against its detachment. For the evaluation of arguments in favor of detaching obligations we use a Dung-style argumentation-theoretical semantics. We illustrate the modularity of the general framework by considering some extensions, and we compare the framework to some related approaches from the literature.Comment: This is our submission to DEON 2016, including the technical appendi

Abstract Argumentation and Explanation Applied to Scientific Debates

Abstract argumentation has been shown to be a powerful tool within many fields such as artificial intelligence, logic and legal reasoning. In this paper we enhance Dung's well-known abstract argumentation framework with explanatory capabilities. We show that an explanatory argumentation framework (EAF) obtained in this way is a useful tool for the modeling of scientific debates. On the one hand, EAFs allow for the representation of explanatory and justificatory arguments constituting rivaling scientific views. On the other hand, different procedures for selecting arguments, corresponding to different methodological and epistemic requirements of theory evaluation, can be formulated in view of our framework

Epistemic Effects of Scientific Interaction: Approaching the Question with an Argumentative Agent-Based Model

The question whether increased interaction among scientists is beneficial or harmful for their efficiency in acquiring knowledge has in recent years been tackled by means of agent-based models (ABMs) (e.g. Zollman 2007, 2010; Grim 2009; Grim et al. 2013). Nevertheless, the relevance of some of these results for actual scientific practice has been questioned in view of specific parameter choices used in the simulations (Rosenstock et al. 2016). In this paper we present a novel ABM that aims at tackling the same question, while representing scientific interaction in terms of argumentative exchange. In this way we examine the robustness of previously obtained results under different modeling choices

Heuristic Reevaluation of the Bacterial Hypothesis of Peptic Ulcer Disease in the 1950s

Throughout the first half of the twentieth century the research on peptic ulcer disease (PUD) focused on two rivaling hypothesis: the “acidity” and the “bacterial” one. According to the received view, the latter was dismissed during the 1950s only to be revived with Warren’s and Marshall’s discovery of Helicobacter pylori in the 1980s. In this paper we investigate why the bacterial hypothesis was largely abandoned in the 1950s, and whether there were good epistemic reasons for its dismissal. Of special interest for our research question is Palmer’s 1954 large-scale study, which challenged the bacterial hypothesis with serious counter-evidence, and which by many scholars is considered as the shifting point in the research on PUD. However, we show that: (1) The perceived refutatory impact of Palmer’s study was disproportionate to its methodological rigor. This undermines its perceived status as a crucial experiment against the bacterial hypothesis. (2) In view of this and other considerations we argue that the bacterial hypothesis was worthy of pursuit in the 1950s

Surface band structure of Bi1−xSbx\text{Bi}_{1-x}\text{Sb}_{x}(111)

Theoretical and experimental studies agree that $\text{Bi}_{1-x}\text{Sb}_{x}$ ($0.07 \leq x \leq 0.21$) to be a three-dimensional topological insulator. However, there is still a debate on the corresponding $\text{Bi}_{1-x}\text{Sb}_{x}$(111) surface band structure. While three spin polarized bands have been claimed experimentally, theoretically, only two surface bands appear, with the third band being attributed to surface imperfections. Here, we address this controversy using angle-resolved photoemission spectroscopy (ARPES) on $\text{Bi}_{1-x}\text{Sb}_{x}$ films. To minimize surface imperfections, we have optimized the sample growth recipe. We have measured the evolution of the surface band structure of $\text{Bi}_{1-x}\text{Sb}_{x}$ with $x$ increasing gradually from $x = 0$ to $x = 0.6$. Our ARPES data show better agreement with the theoretical calculations, where the system is topologically non-trivial with two surface bands