Data‐driven approaches to information access

This paper summarizes three lines of research that are motivated by the practical problem of helping users find information from external data sources, most notably computers. The application areas include information retrieval, text categorization, and question answering. A common theme in these applications is that practical information access problems can be solved by analyzing the statistical properties of words in large volumes of real world texts. The same statistical properties constrain human performance, thus we believe that solutions to practical information access problems can shed light on human knowledge representation and reasoning.     

PARADIGMS OF BELIEF, THEORY AND METATHEORY

Abstract. My account of the recent turnabout in the treatment of mental states in science and its basis in a modified concept of causal determinism and my claim that this opens the way for beliefs and values consistent with science are here reaffirmed in response to perceived weaknesses and "inherent incompleteness." Contested issues are reviewed to better clarify the main thesis. An inherent weakness in respect to deep spiritual needs is recognized and tentative remedial measures explored.     

汉字词特征语义提取的实验研究

本研究运用语义判断的方法,对汉字词特征语义的提取做了初步的探讨,被试是28名大学生。实验结果表明,汉字形声字的义符在汉字词定义特征语义提取中有重要作用,在义符与词义一致时,能加速词的定义特征语义的提取。义符对词的特有特征的语义提取无作用,而特有特征的强度能很好地预测提取时间。本研究还发现,词的熟悉性和该词距其上属的语义距离对词的定义特征的语义提取亦有重要影响。     

Circular definitions,circular explanations,and infinite regresses

This paper discusses some of the ways in which circular definitions and circular explanations entail or fail to entail infinite regresses. And since not all infinite regresses are vicious, a few criteria of viciousness are examined in order to determine when the entailment of a regress refutes a circular definition or a circular explanation.I would like to thank Professors Robert Tully, Howard Sobel, and Derek Allen for their constructive comments.     

语义联系类型和强度对预期推理生成的制约作用

首先采用开放式问卷实验方法,由被试生成日常生活中的事件以及组成这些事件的各种活动和活动的参加者。然后,对这些事件熟悉性、对活动的典型性和可区分性三个维度进行主观评价,形成事件以及每个事件活动序列,并据此编制实验材料。实验主要考察活动的典型性和可区分性对于熟悉性高的事件的预期推理的影响,以及不同工作记忆能力的被试进行事件预期推理时的加工模式。实验结果表明：（１）高工艺记忆能力的被试对事件的预期量小于     

Concurrent fixed-interval variable-ratio schedules and the matching relation

Five rats responded under concurrent fixed-interval variable-ratio schedules of food reinforcement. Fixed-interval values ranged from 50-seconds to 300-seconds and variable-ratio values ranged from 30 to 360; a five-second changeover delay was in effect throughout the experiment. The relations between reinforcement ratios obtained from the two schedules and the ratios of responses and time spent on the schedules were described by Baum's (1974) generalized matching equation. All subjects undermatched both response and time ratios to reinforcement ratios, and all subjects displayed systematic bias in favor of the variable-ratio schedules. Response ratios undermatched reinforcement ratios less than did time ratios, but response ratios produced greater bias than did time ratios for every subject and for the group as a whole. Local rates of responding were generally higher on the variable-ratio than on the fixed-interval schedules. When responding was maintained by both schedules, a period of no responding on either schedule immediately after fixed-interval reinforcement typically was followed by high-rate responding on the variable-ratio schedule. At short fixed-interval values, when a changeover to the fixed-interval schedule was made, responding usually continued until fixed-interval reinforcement was obtained; at longer values, a changeover back to the variable-ratio schedule usually occurred when fixed-interval reinforcement was not forthcoming within a few seconds, and responding then alternated between the two schedules every few seconds until fixed-interval reinforcement finally was obtained.     

词汇共现频率视角下语义联想效应及其神经机制

词汇识别与记忆受到词汇之间语义联想关系的影响。鉴于自由联想方法建立词汇语义联想关系的局限性, 研究者们提出用共现联想法建立词汇之间的语义联想关系。本文对词汇共现频率视角下的语义联想效应及其神经机制的研究进行分析发现, 语义联想的丰富程度和关联程度影响词汇的加工; 与少语义联想词相比, 多语义联想词导致P200波幅增大和N400波幅减小; 语义联想加工涉及的脑区主要是额上回和左内侧颞叶区域。未来研究需要探讨自由联想法和共现联想法建立语义联想关系的差异, 基于共现联想法进一步地探究语义联想的行为规律和神经机制, 并从共现联想的角度开展汉语语义联想效应及神经机制的研究。     

象似性和手语学习经验对中国手语-汉语跨模态语义启动效应的影响

采用启动条件下的词汇判断任务,考察熟练手语使用者和无手语经验成年听人的跨模态语义启动效应。结果发现：1)在象似词条件下,两组被试判断汉语语义相关词的反应时均快于语义无关词,说明手语象似词和汉语词之间存在跨模态语义启动效应。2)在非象似词条件下,仅手语熟练被试判断汉语语义相关词的反应时快于语义无关词,无手语经验被试判断汉语语义相关词和无关词的速度没有差异。这是由于前者心理词库中的手语词和口语词共享语义表征,而后者主要依赖手语象似词的视觉模拟性。整个研究表明,中国手语和汉语间存在跨模态语义启动效应,但该效应受到手语词象似性和手语学习经历的调节。