首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   857篇
  免费   77篇
  国内免费   65篇
  2024年   2篇
  2023年   7篇
  2022年   11篇
  2021年   30篇
  2020年   33篇
  2019年   32篇
  2018年   37篇
  2017年   45篇
  2016年   48篇
  2015年   37篇
  2014年   69篇
  2013年   178篇
  2012年   31篇
  2011年   52篇
  2010年   25篇
  2009年   59篇
  2008年   62篇
  2007年   58篇
  2006年   39篇
  2005年   26篇
  2004年   26篇
  2003年   20篇
  2002年   24篇
  2001年   7篇
  2000年   8篇
  1999年   10篇
  1998年   9篇
  1997年   4篇
  1996年   3篇
  1994年   3篇
  1990年   1篇
  1988年   1篇
  1983年   2篇
排序方式: 共有999条查询结果,搜索用时 15 毫秒
901.
Three-Mode Component Analysis with Crisp or Fuzzy Partition of Units   总被引:1,自引:0,他引:1  
A new methodology is proposed for the simultaneous reduction of units, variables, and occasions of a three-mode data set. Units are partitioned into a reduced number of classes, while, simultaneously, components for variables and occasions accounting for the largest common information for the classification are identified. The model is a constrained three-mode factor analysis and it can be seen as a generalization of the REDKM model proposed by De Soete and Carroll for two-mode data. The least squares fitting problem is mathematically formalized as a constrained problem in continuous and discrete variables. An iterative alternating least squares algorithm is proposed to give an efficient solution to this minimization problem in the crisp and fuzzy classification context. The performances of the proposed methodology are investigated by a simulation study comparing our model with other competing methodologies. Different procedures for starting the proposed algorithm have also been tested. A discussion of some interesting differences in the results follows. Finally, an application to real data illustrates the ability of the proposed model to provide substantive insights into the data complexities.  相似文献   
902.
Gupta-Belnap-style circular definitions use all real numbers as possible starting points of revision sequences. In that sense they are boldface definitions. We discuss lightface versions of circular definitions and boldface versions of inductive definitions.  相似文献   
903.
Four studies investigated whether and when infants connect information about an actor's affect and perception to their action. Arguably, this may be a crucial way in which infants come to recognize the intentional behaviors of others. In Study 1 an actor grasped one of two objects in a situation where cues from the actor's gaze and expression could serve to determine which object would be grasped, specifically the actor first looked at and emoted positively about one object but not the other. Twelve-month-olds, but not 8-month-olds, recognized that the actor was likely to grasp the object which she had visually regarded with positive affect. Studies 2, 3, and 4 replicated the main finding from Study 1 with 12- and 14-month-olds and included several contrasting conditions and controls. These studies provide evidence that the ability to use information about an adult's direction of gaze and emotional expression to predict action is both present, and developing at the end of the first year of life.  相似文献   
904.
Children's concurrent success on false belief tasks and their handling of two labels for one object (e.g., bunny/rabbit) has been interpreted as demonstrating understanding about the essential features of representation. Three experiments reveal the limitations in 5-year-olds' understanding for both mental and linguistic representations. We report relatively poor performance on a task involving two labels for one object (e.g., dice/eraser) which required children to treat another's knowledge as representing only some of the feature of its real referent: Dice but not eraser. Five year olds who made errors also had difficulty handling the fact that a written word 'dice' referring to such a dice/eraser, can also be applied to a standard dice but not to a standard eraser. These children lacked metalinguistic awareness of words as entities that both refer and describe.  相似文献   
905.
Abu-Akel A  Bailey AL 《Cognition》2001,80(3):263-281
Numerous measures have been employed in the last 17 years to assess theory of mind (ToM). The literature reports marked variability in the age at which children succeed on these measures. To account for this variability, researchers have provided explanations ranging from cognitive shifts and voids to the inability to understand the language of the tasks or to social/pragmatic considerations, all of which tell us little if anything about the internal mechanism underlying ToM. The main purpose of this paper is to provide a comprehensive theoretical account of children's success and the discrepancies found across different ToM tasks. We test the hypothesis that children's understanding of ToM is sensitive to the basic elements of language, that is, to whether the language is indexical or symbolic. Support for this account was found in the analysis of selected test protocols in four published studies of ToM, and new data collected from 53 children (4--6 years) which showed that a higher percentage of children succeeded on tasks with a high ratio of indexical to symbolic references than on tasks with a high ratio of symbolic to indexical references. There was also a main effect of age with older children succeeding at higher rates on both tasks than younger children. Our findings suggest that indexical representation can afford ToM understanding in 4-year-olds, but is not sufficient for a more mature ToM. The latter requires symbolic representation that was demonstrated by the majority of 5--6-year-olds.  相似文献   
906.
Researchers frequently have only categorical data to analyze and cannot, for theoretical or methodological reasons, assume that the observed variables are discrete representations of an underlying continuous variable. We present latent class analysis as an alternative method of measuring latent variables in these circumstances. Latent class analysis does not require the assumptions of factor analyses about the nature of manifest and latent variables, but does allow the use of more precise model selection than techniques such as cluster analysis. We modeled the lifetime substance use of American Indian youth. The latent class model of American Indian teenagers' substance use had four classes: Abstaining, Predominantly Alcohol, Predominantly Alcohol and Marijuana, and Plural Substance. We then demonstrated the usefulness of this latent variable by using it to differentiate levels of several variables in a manner consistent with Social Cognitive Theory.  相似文献   
907.
Transformative Learning Theory and pedagogies leverage disruptive experiences as catalysts for learning and teaching. By facilitating processes of critical analysis and reflection that challenge assumptions, transformative learning reframes what counts as knowledge and the sources and processes for gaining and producing it. Students develop a broader range of perspectives on and entry points for learning and behavior change engaging cognition, embodiment, aesthetics, emotions, and ethics (see Mezirow 1991 and Figures 1 and 2). The open‐inquiry, multi‐modal nature of transformative learning defies most traditional assessment strategies. This article demonstrates that grounded theory offers the rigorous qualitative analysis needed to document and track transformative learning outcomes in practice. By applying a grounded theory approach to data from over eighty student portfolios across several iterations of a Religion and Ecology course at Emory University, this article demonstrates a successful and replicable assessment of transformative learning pedagogies.  相似文献   
908.
ObjectivesHabit has been proposed as an explanation of why prior behavior is a good predictor of later behavior. This study examined whether habit mediates the relationship between prior and later physical activity (PA), within the framework of the attitude-social influences-efficacy (ASE) model and the theory of planned behavior (TPB).DesignA longitudinal design was used.MethodsA total of 1976 older adults completed questionnaires on ASE/TPB constructs and PA at baseline, intention at three months, habit at six months, and PA at twelve months.ResultsPath analyses showed that habit significantly mediates the relationship between prior and later PA, after ASE/TPB variables were taken into account.ConclusionsHabit is a partial solution to the question why prior PA is a good predictor of later PA. It is recommended to incorporate habit into the ASE/TPB model.  相似文献   
909.
Experts with video game experience, in contrast to non-experienced persons, are superior in multiple domains of visual attention. However, it is an open question which basic aspects of attention underlie this superiority. We approached this question using the framework of Theory of Visual Attention (TVA) with tools that allowed us to assess various parameters that are related to different visual attention aspects (e.g., perception threshold, processing speed, visual short-term memory storage capacity, top-down control, spatial distribution of attention) and that are measurable on the same experimental basis. In Experiment 1, we found advantages of video game experts in perception threshold and visual processing speed; the latter being restricted to the lower positions of the used computer display. The observed advantages were not significantly moderated by general person-related characteristics such as personality traits, sensation seeking, intelligence, social anxiety, or health status. Experiment 2 tested a potential causal link between the expert advantages and video game practice with an intervention protocol. It found no effects of action video gaming on perception threshold, visual short-term memory storage capacity, iconic memory storage, top-down control, and spatial distribution of attention after 15 days of training. However, observations of a selected improvement of processing speed at the lower positions of the computer screen after video game training and of retest effects are suggestive for limited possibilities to improve basic aspects of visual attention (TVA) with practice.  相似文献   
910.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号