On the sampling theory roundations of item response theory models

Item response theory (IT) models are now in common use for the analysis of dichotomous item responses. This paper examines the sampling theory foundations for statistical inference in these models. The discussion includes: some history on the stochastic subject versus the random sampling interpretations of the probability in IRT models; the relationship between three versions of maximum likelihood estimation for IRT models; estimating versus estimating -predictors; IRT models and loglinear models; the identifiability of IRT models; and the role of robustness and Bayesian statistics from the sampling theory perspective.A presidential address can serve many different functions. This one is a report of investigations I started at least ten years ago to understand what IRT was all about. It is a decidedly one-sided view, but I hope it stimulates controversy and further research. I have profited from discussions of this material with many people including: Brian Junker, Charles Lewis, Nicholas Longford, Robert Mislevy, Ivo Molenaar, Donald Rock, Donald Rubin, Lynne Steinberg, Martha Stocking, William Stout, Dorothy Thayer, David Thissen, Wim van der Linden, Howard Wainer, and Marilyn Wingersky. Of course, none of them is responsible for any errors or misstatements in this paper. The research was supported in part by the Cognitive Science Program, Office of Naval Research under Contract No. Nooo14-87-K-0730 and by the Program Statistics Research Project of Educational Testing Service.     

Mission and People with Disabilities

This article begins with a few thoughts and some historical and canonical encounters about how lay and ordained people with disabilities have been involved in Orthodox mission work in the past. It then presents two concrete contemporary situations in which people with disabilities are involved in Orthodox ordained ministry work despite the persisting tradition that disabled people not be ordained. The first example is taken from the Eritrean Orthodox Tewahedo Church, where the involvement of people with disabilities in both ordained and lay ministry provides significant support for a church that lives in a delicate situation. The second example is taken from the Romanian Orthodox Church and presents the case of Father Theophilus P?r?ian, one of the most prominent contemporary Romanian Orthodox monastic figures, who served as an ordained priest despite his disability. This article pleads for a deeper involvement of disabled people in both ordained and lay ministry in Orthodox churches.     

A Critical Examination of Anselm's Ontological Argument

This paper argues that St.Anselm's distinction of the two senses of existence in his ontological argument for the existence of God renders Paul Tillich's refutation of it invalid.At the same time,Anselm misuses the two types of existence in his ontological comparison,leading to a logical contradiction between the different kinds and degrees of existence.Since Anselm's idea of different reference subjects does not coherently solve this logical absurdity,Anselm's ontological argument falls well short of being a successful approach to establishing the existence of God.     

中国古代“孝”文化的两重性

孝的本义是“善事父母”。因为人为父母所生养而成长 ,应该给以回报 ,所以孔孟主张对父母尽孝。先秦儒家还提出父慈子孝的对等关系 ,在道德人格上是平等的。秦汉大一统以后 ,移孝作忠 ,伦理向政治伸延 ,君父对臣子形成统治与被统治的关系。汉朝称以孝治天下 ,建立察孝廉、奖孝悌的制度。对孝道的提倡 ,用以造就一批父慈子孝、兄友弟恭的孝悌家庭 ,对以家族为本位、家国同构的中国古代 ,儿女尽孝能和睦家庭 ,进而安定社会 ,增强中华民族凝聚力 ,有一定的正面作用。同时把孝亲与忠君联系起来 ,所谓忠臣出于孝子之门 ,对于维护汉皇朝的统治亦有安定的作用。但是历朝的孝治政策亦有负面效应。由于朝廷奖励孝子 ,有的人就弄虚作假 ,败坏社会风气 ,把孝道作为沽名钓誉的工具。有的虽然真心尽孝 ,但措施不当 ,形成愚昧行为。正面与负面就形成中国古代孝文化的两重性。     

Stimulus complexity and prospective timing: clues for a parallel process model of time perception

Whereas many studies have considered the role of attention in prospective timing, fewer have established relations between movement complexity and prospective timing. The present study aims at assessing to what extent motion complexity interferes with prospective timing and at delineating a neuropsychophysical plausible model. We have thus designed a visual paradigm presenting stimuli in sequential pairs (reference comparison interval). Stimuli are motionless or moving according to different complexities, and stimulus complexities are intermixed within each pair. To prevent a possible attention-sharing effect, no concurrent task was required. Our study suggests that movement complexity is a key component of duration perception, and that the relative judgement of durations depends on spatio-temporal features of stimuli. In particular, it shows that movement complexity can bias subjects’ perception and performance, and that subjects detect that comparison intervals are longer than reference before their end. In the discussion, we advocate that the classical internal clock model cannot easily account for our results. Consequently, we propose a model for time perception, based on a parallel processing between comparison interval perception and the reconstruction of the reference duration.     

调强适形放射治疗的多学科整合

调强适形放射治疗是放射治疗100余年历史中的一个革命性进步,能使高剂量的立体分布适合外形非常不规则甚至怪异的肿瘤,调整靶区内诸点的输出剂量率,显著提高肿瘤放疗的疗效。近年计算机技术、放射物理学、放射生物学、分子生物学、影像学特别是功能性影像学的快速发展以及多门边缘学科之间的有机结合,为调强适形放射治疗提供在靶区三维精确模拟定位、立体定向定位摆位框架、逆向治疗计划系统、调强治疗机等方面的发展基础。调强适形放射治疗——多元化医学理论下的医疗方法将在学科交叉、综合发展中进一步巩固。     

Shared intention and personal intentions

This article explores the question: what is it for two or more people to intend to do something in the future? In a technical phrase, what is it for people to share an intention? Extending and refining earlier work of the author’s, it argues for three criteria of adequacy for an account of shared intention (the disjunction, concurrence, and obligation criteria) and offers an account that satisfies them. According to this account, in technical terms explained in the paper, people share an intention when and only when they are jointly committed to intend as a body to do such-and-such in the future. This account is compared and contrasted with the common approach that treats shared intention as a matter of personal intentions, with particular reference to the work of Michael Bratman.     

论社会主义荣辱观的主体层次性

对社会主义荣辱观进行主体层次性划分,不仅是构建和谐社会的客观要求,而且是道德层次性研究的内在呼唤。胡锦涛同志提出的“八荣八耻”社会主义荣辱观应针对不同的道德主体各有侧重,并针对不同的道德主体切实加强社会主义荣辱观教育。     

Does P3 Reflect Attentional or Memory Performances,or Cognition more Generally?

The study evaluated the off-line relationship of attention, memory and other cognitive performances with the auditory event-related potentials P3 (P300) and N2. The sample comprised 200 middle-aged construction workers. Verbal, visuomotor and memory tests were administered. Attentional domains were examined using CogniSpeed software. Slowed reaction times in the test of sustained attention (vigilance) were associated with delayed P3 latency (p < 0.001) and decreased P3 amplitude (p = 0.005), as well as with delayed N2 latency (p < 0.001). Visuomotor slowing in Digit Symbol was also related to delayed P3 latency (p = 0.030) and decreased P3 amplitude (p = 0.014). In contrast, mild cognitive impairment, short- and long-term memory, and concentrating or sharing attention with high working memory demands were not related to P3. The results suggest that P3 is linked to attentional performance with low working memory demands rather than to effortful working memory updating, retrieval from memory stores, or mild cognitive impairment.     

医学人体试验中受试者权益保护问题探微——对《赫尔辛基宣言》修订的几点思考

《赫尔辛基宣言》自颁行以来已六次修订,为适应医学研究领域的新情势,世界医学会征询中华医学会对2008年版《赫尔辛基宣言》的修改意见,中华医学会委托医学伦理学分会组织专家进行意见征集与调研活动。在整理和总结上述修订意见的基础上,进一步研究探讨了关于受试者知情同意、受试者风险评估、受试者权益保障、医学伦理委员会伦理监督职能、程序伦理等问题,并提出了基于中国国情的考虑与建议,以期借鉴国际医学伦理典籍,共谋我国医学伦理的发展,为保护受试者方面贡献力量。