Levels of modality for BDI Logic

The use of rational agents for modelling real world problems has both been heavily investigated and become well accepted, with BDI (Beliefs, Desires, and Intentions) Logic being a widely used architecture to represent and reason about rational agency. However, in the real world, we often have to deal with different levels of confidence in the beliefs we hold, desires we have, and intentions that we commit to. This paper extends our previous framework that integrated qualitative levels of beliefs, desires, and intentions into BDI Logic. We describe an expanded set of axioms and properties of the extended logic. We present a modular structure for the semantics which involves a non-normal Kripke type semantics that may be used for other agent systems. Further, we demonstrate the usefulness of our framework with a scheduling task example.     

An analytic tableau calculus for a temporalised belief logic

A tableau is a refutation-based decision procedure for a related logic, and is among the most popular proof procedures for modal logics. In this paper, we present a labelled tableau calculus for a temporalised belief logic called TML⁺, which is obtained by adding a linear-time temporal logic onto a belief logic by the temporalisation method of Finger and Gabbay. We first establish the soundness and the completeness of the labelled tableau calculus based on the soundness and completeness results of its constituent logics. We then sketch a resolution-type proof procedure that complements the tableau calculus and also propose a model checking algorithm for TML⁺ based on the recent results for model checking procedures for temporalised logics. TML⁺ is suitable for formalising trust and agent beliefs and reasoning about their evolution for agent-based systems. Based on the logic TML⁺, the proposed labelled tableau calculus could be used for analysis, design and verification of agent-based systems operating in dynamic environments.     

Thinking about representations: the case of opaque contexts

To address the question of whether young children are differentially sensitive to referential opacity, an advanced Theory of Mind skill, we assessed 4-, 6-, and 8-year-olds on three types of opaque contexts: epistemic, quotational, and intentional. Children’s performance improved as a function of age and varied significantly by opacity type. Performance was best for epistemic opacity (using the verb “know”) and poorest for intentional opacity (using “mean to”), with quotational opacity (using “said”) falling in-between. Importantly, the current results suggest that children’s sensitivity to referential opacity is not an all-or-nothing competence but rather one that varies across the contexts examined. Possible reasons for this variability are discussed.     

积极情景线索对内隐攻击性的影响

通过向被试呈现代表积极情景线索的材料(一段含有互助、和谐信息的公益短片),运用内隐联想测验(IAT)范式,从内隐社会认知的角度来研究积极情境线索对个体内隐攻击性的影响,并分析这种影响是否具有性别差异。结果表明:未观看积极情景线索材料的被试表现出显著的内隐攻击性,而观看积极情景线索材料的被试的内隐攻击性不显著;积极情景线索的主效应显著,且这一效应不存在性别差异。这说明,积极情景线索能有效抑制个体的内隐攻击性,并支持自我攻击信念IAT是测量个体内隐攻击性的有效工具。     

错误信念任务中的知识偏差

有观点指出,年幼儿童在错误信念任务上的发展变化,不是发生了概念变化的质变,而是知识偏差的表现。知识偏差是指当我们尝试理解一个更不知情的观点时,不能忽略自己拥有的额外信息并受此影响而产生偏差的倾向。本文对知识偏差的含义及其在错误信念任务中可能产生的影响做了较为详细的综述和分析,并就在错误信念任务中消除知识偏差影响的可能性进行了探讨。     

Towards a “Sophisticated” Model of Belief Dynamics. Part I: The General Framework

It is well-known that classical models of belief are not realistic representations of human doxastic capacity; equally, models of actions involving beliefs, such as decisions based on beliefs, or changes of beliefs, suffer from a similar inaccuracies. In this paper, a general framework is presented which permits a more realistic modelling both of instantaneous states of belief, and of the operations involving them. This framework is motivated by some of the inadequacies of existing models, which it overcomes, whilst retaining technical rigour in so far as it relies on known, natural logical and mathematical notions. The companion paper (Towards a “sophisticated” model of belief dynamics. Part II) contains an application of this framework to the particular case of belief revision. Presented by Hannes Leitgeb     

The virtues of epistemic conservatism

Although several important methodologies implicitly assume the truth of epistemic conservatism, the view that holding a belief confers some measure of justification on the belief, recent criticisms have led some to conclude that epistemic conservatism is an implausible view. That conclusion is mistaken. In this article, I propose a new formulation of epistemic conservatism that is not susceptible to the criticisms leveled at earlier formulations of epistemic conservatism. In addition to withstanding these criticisms, this formulation of epistemic conservatism has several benefits. First, this formulation has the benefits of earlier formulations of epistemic conservatism, that is to say it makes sense of our intuitions about justification in regard to both memory beliefs and beliefs for which we have forgotten our evidence. Second, it provides a good way of responding to the skeptic’s challenge concerning the possibility of possessing knowledge of the external world posed by the Alternative Hypotheses argument. Third, it provides responses to both forms of a new skeptical problem plaguing basic knowledge structure theories, the Problem of Easy Knowledge formulated by Stewart Cohen. I argue that given the many benefits of this formulation of epistemic conservatism and the fact that it is not vulnerable to the criticisms that undermine earlier formulations of epistemic conservatism, this formulation of epistemic conservatism is a plausible view to maintain.     

Evaluating dialectical structures with Bayesian methods

This paper shows how complex argumentation, analyzed as dialectical structures, can be evaluated within a Bayesian framework by interpreting them as coherence constraints on subjective degrees of belief. A dialectical structure is a set of arguments (premiss-conclusion structure) among which support- and attack-relations hold. This approach addresses the observation that some theses in a debate can be better justified than others and thus fixes a shortcoming of a theory of defeasible reasoning which applies the bivalence principle to argument evaluations by assigning them the status of being either defeated or undefeated. Evaluation procedures which are based on the principle of bivalence can, however, be embedded as a special case within the Bayesian framework. The approach developed in this paper rests on the assumptions that arguments can be reconstructed as deductively valid and that complex argumentation can be reconstructed such that premisses of arguments with equivalent conclusions are pairwise independent.     

儿童在错误信念任务上的知识偏差

采用3种任务考查儿童在错误信念（FB）推理中是否存在知识偏差。被试为60名3—5岁幼儿,结果表明,对于3岁及4岁儿童来说,FB任务是存在知识偏差的。知识偏差的大小与年龄呈负相关关系,3岁与4岁、4岁与5岁儿童的知识偏差的大小均有显著差异。     

聋童与正常儿童对多种信念的认知

选取了122名3～12岁聋童,并分别用65名3～5岁的正常儿童作对照,开展了2个实验系列,探讨了儿童的正确信念、一级错误信念及二级错误信念认知的发展特点.结果如下: (1)聋童及正常儿童信念认知的发展过程中,无论是关于正确信念,还是关于一级错误信念,都是先发展自我信念认知,再发展他人信念认知;(2)关于正确信念、一级错误信念和二级错误信念认知的发展,聋童都比正常儿童滞后,但两者的发展趋势一致; (3)手语聋童在信念认知上略好于口语聋童; (4)父母为聋人或父母会手语的聋童,以及兄弟姐妹会手语的聋童,其信念认知水平要比其他聋童好.