Assessing theories,Bayes style

The problem addressed in this paper is “the main epistemic problem concerning science”, viz. “the explication of how we compare and evaluate theories [...] in the light of the available evidence” (van Fraassen, BC, 1983, Theory comparison and relevant Evidence. In J. Earman (Ed.), Testing scientific theories (pp. 27–42). Minneapolis: University of Minnesota Press). Sections 1– 3 contain the general plausibility-informativeness theory of theory assessment. In a nutshell, the message is (1) that there are two values a theory should exhibit: truth and informativeness—measured respectively by a truth indicator and a strength indicator; (2) that these two values are conflicting in the sense that the former is a decreasing and the latter an increasing function of the logical strength of the theory to be assessed; and (3) that in assessing a given theory by the available data one should weigh between these two conflicting aspects in such a way that any surplus in informativeness succeeds, if the shortfall in plausibility is small enough. Particular accounts of this general theory arise by inserting particular strength indicators and truth indicators. In Section 4 the theory is spelt out for the Bayesian paradigm of subjective probabilities. It is then compared to incremental Bayesian confirmation theory. Section 4 closes by asking whether it is likely to be lovely. Section 5 discusses a few problems of confirmation theory in the light of the present approach. In particular, it is briefly indicated how the present account gives rise to a new analysis of Hempel’s conditions of adequacy for any relation of confirmation (Hempel, CG, 1945, Studies in the logic of comfirmation. Mind, 54, 1–26, 97–121.), differing from the one Carnap gave in § 87 of his Logical foundations of probability (1962, Chicago: University of Chicago Press). Section 6 adresses the question of justification any theory of theory assessment has to face: why should one stick to theories given high assessment values rather than to any other theories? The answer given by the Bayesian version of the account presented in section 4 is that one should accept theories given high assessment values, because, in the medium run, theory assessment almost surely takes one to the most informative among all true theories when presented separating data. The concluding section 7 continues the comparison between the present account and incremental Bayesian confirmation theory.     

Ethical Specificities: Repositioning Indian Ethics

The essay is a review discussion of Indian Ethics in the context of a recent volume of essays. The attempt is to identify some of the issues that are now on the frontier of Indian ethics or that are likely to appear on that frontier in the coming years. Sasheej Hegde  teaches sociology at the University of Hyderabad, India. His work straddles many disciplines and sociohistorical settings, although in recent times he has been concerned with formulating a comparative agenda on law and ethics.     

Indiscriminability as Indiscernibility by Default

Most solutions to the sorites reject its major premise, i.e. the quantified conditional . This rejection appears to imply a discrimination between two elements that are supposed to be indiscriminable. Thus, the puzzle of the sorites involves in a fundamental way the notion of indiscriminability. This paper analyzes this relation and formalizes it, in a way that makes the rejection of the major premise more palatable. The intuitive idea is that we consider two elements indiscriminable by default, i.e. unless we know some information that discriminates between them. Specifically, following Rough Set Theory, two elements are defined to be indiscernible if they agree on the vague property in question. Then, a is defined to be indiscriminable from b if a is indiscernible by default from b. That is to say, a is indiscriminable from b if it is consistent to assume that a and b agree on the relevant vague property. Indiscernibility by default is formalized with the use of Default Logic, and is shown to have intuitively desirable properties: it is entailed by equality, is reflexive and symmetric. And while the relation is neither transitive nor substitutive, it is “almost” substitutive. This definition of indiscriminability is incorporated into three major theories of vagueness, namely the supervaluationist, epistemic, and contextualist views. Each one of these theories is reduced to a different strategy dealing with multiple extensions in Default Logic, and the rejection of the major premise is shown to follow naturally. Thus, while the proposed notion of indiscriminability does not solve the sorites by itself, it does make the unintuitive conclusion of many of its proposed solutions—the rejection of the major premise—a bit easier to accept.     

Do Theory of Mind and Executive Function Deficits Underlie the Adverse Outcomes Associated with Profound Early Deprivation?: Findings from the English and Romanian Adoptees Study

Theory of Mind (ToM) and Executive Function (EF) have been associated with autism and with attention-deficit hyperactivity disorder (ADHD), and hence might play a role in similar syndromes found following profound early institutional deprivation. In order to examine this possibility the current study included a group of 165 Romanian adoptees, of whom 144 were adopted into the UK from deprived institutional settings before 43months of age, and a group of 52 within-UK adoptees, all adopted before 6months of age. Both groups were assessed at 6 and 11years. The Strange Stories task was used to assess ToM and the Stroop task was used to assess EF, both at age 11. The Romanian adoptees displayed deficits in both ToM and EF compared with the within-UK adoptee group. The degree of deficit was greater for children who had experienced more than 6months of institutional deprivation. Deficits in both domains (ToM and EF) were associated with each of the three apparently deprivation-specific problems, namely quasi-autism, disinhibited attachment and inattention/overactivity. Statistical analyses indicated a mediating role for both ToM and EF with respect to quasi-autism; possibly a partial mediating role for EF with respect to inattention/overactivity; and probably no mediating role for either ToM or EF in the case of disinhibited attachment. In conclusion, there is evidence for a possible mediating role for ToM and EF in the development of some apparently deprivation-specific difficulties in institution-reared Romanian adoptees, but neither accounts for the overall pattern of deprivation-related difficulties.     

The role of preschoolers' social understanding in evaluating the informativeness of causal interventions

Preschoolers use information from interventions, namely intentional actions, to make causal inferences. We asked whether children consider some interventions to be more informative than others based on two components of an actor’s knowledge state: whether an actor possesses causal knowledge, and whether an actor is allowed to use their knowledge in a given situation. Three- and four-year-olds saw a novel toy that activated in the presence of certain objects. Two actors, one knowledgeable about the toy and one ignorant, each tried to activate the toy with an object. In Experiment 1, either the actors chose objects or the child chose for them. In Experiment 2, the actors chose objects blindfolded. Objects were always placed on the toy simultaneously, and thus were equally associated with the effect. Preschoolers’ causal inferences favored the knowledgeable actor’s object only when he was allowed to choose it (Experiment 1). Thus, children consider both personal and situational constraints on knowledge when evaluating the informativeness of causal interventions.     

Three- and four-year-olds spontaneously use others' past performance to guide their learning

A wealth of human knowledge is acquired by attending to information provided by other people – but some people are more credible sources than others. In two experiments, we explored whether young children spontaneously keep track of an individual’s history of being accurate or inaccurate and use this information to facilitate subsequent learning. We found that 3- and 4-year-olds favor a previously accurate individual when learning new words and learning new object functions and applied the principle of mutual exclusivity to the newly learned words but not the newly learned functions. These findings expand upon previous research in a number of ways, most importantly by showing that (a) children spontaneously keep track of an individual’s history and use it to guide subsequent learning without any prompting, and (b) children’s sensitivity to others’ prior accuracy is not specific to the domain of language.     

Sentences with Strong Psychological Impact in Psychotherapy: Research in Progress

After a brief exposition of Elementary Pragmatic Model about changes in dyadic interactions, the validity and clinical usefulness of the model was evaluated with a newly created test, called SISCI-Sentences. This test is composed of 90 Sentences with strong psychological impact. Administration of this test to non-clinical and clinical participants produced statistically significant differences between the choices of participants in the two groups. Implications of these results for the use of these Sentences in the course of psychotherapy are discussed.

Interpersonal similarity as a social distance dimension: Implications for perception of others’ actions

Building on the assumption that interpersonal similarity is a form of social distance, the current research examines the manner in which similarity influences the representation and judgment of others’ actions. On the basis of a construal level approach, we hypothesized that greater levels of similarity would increase the relative weight of subordinate and secondary features of information in judgments of others’ actions. The results of four experiments showed that compared to corresponding judgments of a dissimilar target, participants exposed to a similar target person identified that person’s actions in relatively more subordinate means-related rather than superordinate ends-related terms (Experiment 1), perceived his or her actions to be determined more by feasibility and less by desirability concerns (Experiment 3), and gave more weight to secondary aspects in judgments of the target’s decisions (Experiment 2) and performance (Experiment 4). Implications for the study of interpersonal similarity, as well as social distance in general, are discussed.     

纵向Rasch模型在大学新生适应性追踪研究中的应用

对1952名大学新生进行适应性调查,其中285人接受了2次以上的追踪调查,所得的多级评分重复测量数据采用纵向Rasch模型进行统计分析。研究应用SAS的GLIMMIX过程对多层Rasch模型参数估计作了新的尝试。结果表明：（1）新生在第一学年内,学习和情绪适应总体呈上升趋势,人际适应呈下降趋势;（2）不同个体入学时的适应状况差异显著,但是随时间变化的趋势、快慢相同;（3）学习适应分量表的项目稳定性较好,而人际、情绪适应的部分项目难度存在时间效应。研究结果对新生辅导具有启示意义     

Narrative accounts of illness in schizophrenia: association of different forms of awareness with neurocognition and social function over time

Awareness of illness in schizophrenia reflects complex storied understanding of the impact of the disorder upon one’s life. Individuals may be aware of their illness in different ways and this may be related to their functioning. A total of 76 adults with schizophrenia were assessed for their awareness of illness, neurocognition, social cognition, and social function concurrently and social function was also assessed at three later time points. A cluster analysis revealed 3 groups: generally full awareness, generally limited awareness, and superficial awareness. Comparisons between these profiles revealed the superficial group had poorer executive function, emotion recognition ability, and capacity for social relationships than the full awareness group, yet had better verbal memory and more social contacts than the limited awareness group. These results suggest assessing the narrative qualities of awareness of illness may reveal unique links with cognition and function, and this may have implications for interventions.