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A general latent variable model is given which includes the specification of a missing data mechanism. This framework allows for an elucidating discussion of existing general multivariate theory bearing on maximum likelihood estimation with missing data. Here, missing completely at random is not a prerequisite for unbiased estimation in large samples, as when using the traditional listwise or pairwise present data approaches. The theory is connected with old and new results in the area of selection and factorial invariance. It is pointed out that in many applications, maximum likelihood estimation with missing data may be carried out by existing structural equation modeling software, such as LISREL and LISCOMP. Several sets of artifical data are generated within the general model framework. The proposed estimator is compared to the two traditional ones and found superior.The research of the first author was supported by grant No. SES-8312583 from the National Science Foundation and by a Spencer Foundation grant. We wish to thank Chuen-Rong Chan for drawing the path diagram.  相似文献   
23.
In some recent papers, the authors and Peter Gärdenfors have defined and studied two different kinds of formal operation, conceived as possible representations of the intuitive process of contracting a theory to eliminate a proposition. These are partial meet contraction (including as limiting cases full meet contraction and maxichoice contraction) and safe contraction. It is known, via the representation theorem for the former, that every safe contraction operation over a theory is a partial meet contraction over that theory. The purpose of the present paper is to study the relationship more finely, by seeking an explicit map between the component orderings involved in each of the two kinds of contraction. It is shown that at least in the finite case a suitable map exists, with the consequence that the relational, transitively relational, and antisymmetrically relational partial meet contraction functions form identifiable subclasses of the safe contraction functions, over any theory finite modulo logical equivalence. In the process of constructing the map, as the composition of four simple transformations, mediating notions of bottom and top contraction are introduced. The study of the infinite case remains open.  相似文献   
24.
In the first experiment, subjects rated the similarity of a sample of pairs of random dot patterns generated from 3 prototypes consisting of either 4, 6, or 9 dots. The results of the experiment tended to confirm the structure imposed on the patterns by the construction method. In the second experiment, subjects learned to classify random patterns generated from 2 prototypes with either short or long interprototype distance and consisting of either 4, 6, or 9 dots in a traditional concept identification task. After acquisition, memory for old and new distortions and the prototype, which was not presented during learning, was assessed. The tendency to call a pattern “new” increased with the distance between the pattern and its prototype. In a subsequent transfer test, all subjects saw patterns of either 4, 6, or 9 dots. Performance was above chance and the transfer from larger to smaller patterns tended to be greater than the transfer from smaller to larger patterns. This is consistent with a process of schema formation based on features common to most exemplars of the category. The results are discussed in relation to several theories of concept learning and schema abstraction.  相似文献   
25.
Two experiments are reported that examine the nature of the processing of frequency information in Spanish-English bilinguals. In the first study, subjects studied a list of English-only, Spanish-only, and mixed-language words varying in their frequency of occurrence, and under conditions of being either informed or uninformed about the later frequency test. Subjects were then shown pictures represeting the nominally presented items and had to give frequency judgments for the words depicting the objects. Frequency judgments were significantly faster when the words had been presented in a single language, suggesting a summation of access times for the mixed-language words. Instructional conditions had no effect on frequency judgments, but the latency to judge was significantly reduced for the informed subjects. In the second study, using similar acquisition procedures, subjects were shown test words in either the same or the different language from the one in which the words were originally experienced. Subjects demonstrated a clear ability to assign frequencies according to the relationship between acquisition and test language. The data were discussed in terms of supporting the hypothesis of separate bilingual language processing, and implications for the automatic nature of frequency acquisition were also addressed.This article is based on a paper originally presented at the meetings of the Southwestern Psychological Association, San Antonio, April 1983.  相似文献   
26.
A structural equation model is proposed with a generalized measurement part, allowing for dichotomous and ordered categorical variables (indicators) in addition to continuous ones. A computationally feasible three-stage estimator is proposed for any combination of observed variable types. This approach provides large-sample chi-square tests of fit and standard errors of estimates for situations not previously covered. Two multiple-indicator modeling examples are given. One is a simultaneous analysis of two groups with a structural equation model underlying skewed Likert variables. The second is a longitudinal model with a structural model for multivariate probit regressions.This research was supported by Grant No. 81-IJ-CX-0015 from the National Institute of Justice, by Grant No. DA 01070 from the U.S. Public Health Service, and by Grant No. SES-8312583 from the National Science Foundation. I thank Julie Honig for drawing the figures. Requests for reprints should be sent to Bengt Muthén, Graduate School of Education, University of California, Los Angeles, California 90024.  相似文献   
27.
People hold different perspectives about how they think the world is changing or should change. We examined five of these “worldviews” about change: Progress, Golden Age, Endless Cycle, Maintenance, and Balance. In Studies 1–4 (total N = 2733) we established reliable measures of each change worldview, and showed how these help explain when people will support or oppose social change in contexts spanning sustainability, technological innovations, and political elections. In mapping out these relationships we identify how the importance of different change worldviews varies across contexts, with Balance most critical for understanding support for sustainability, Progress/Golden Age important for understanding responses to innovations, and Golden Age uniquely important for preferring Trump/Republicans in the 2016 US election. These relationships were independent of prominent individual differences (e.g., values, political orientation for elections) or context-specific factors (e.g., self-reported innovativeness for responses to innovations). Study 5 (N = 2140) examined generalizability in 10 countries/regions spanning five continents, establishing that these worldviews exhibited metric invariance, but with country/region differences in how change worldviews were related to support for sustainability. These findings show that change worldviews can act as a general “lens” people use to help determine whether to support or oppose social change.  相似文献   
28.
The increasing use of digital technology-based retail services provides new opportunities for digital marketing. In this paper, we investigate how augmented reality (AR) technology can be leveraged as part of the firm's strategy. We explore the online purchase intention through AR smart glasses (ARSG), considering consumers' value assessment through a cost–benefit analysis and the influence of technical, experiential and social AR value drivers. We develop an augmented value-based adoption model addressing four main objectives: (1) Evaluate the effect of the perceived value of ARSG, (2) Evaluate the effect of immersion (experiential dimension), (3) Evaluate the effect of AR devices and technical complexity (technical dimension) and (4) Evaluate the importance of subjective norms (social dimension) on the online purchase intention through AR technology. Based on an ESIC Tech Lab experiment with two types of ARSG from market leaders and AR retail apps, the study uses survey data from 253 participants. The results suggest that the technical dimension has an ambiguous effect, with tech-complexity enhancing directly the perceived value of ARSG for online purchase while reducing the net value of consumers' economic cost–benefit analysis. We find strong evidence that the experiential and social AR dimensions (in the form of immersion and subjective norm) have a significant positive influence on consumers' purchase intention online, which are better predictors than the pure economic cost–benefit assessment (through usefulness and difficulty). Furthermore, the technical innovativeness of consumers is found to increase directly the online purchase intention through ARSG.  相似文献   
29.
Stroke is the main cause of acquired disability in adults, and specific deficits in working memory (WM) are among the most common cognitive consequences. In neuropsychological routine, WM is most of the time investigated in the framework of the multicomponent model (Baddeley & Hitch, 1974, The psychology of learning and motivation, 47). Using a more recent theoretical WM model, the time-based resource-sharing (TBRS) model (Barrouillet et al., 2011, Psychol. Rev., 118, 175), the aim of the present study was to investigate in young post-stroke patients to which extent attentional maintenance is impaired in WM. To address this question, we discarded other factors known to directly influence WM performance, that is processing speed and short-term memory span. We proposed to 53 post-stroke patients and to 63 healthy controls a complex span paradigm in which participants were asked to alternate between the memorization of a series of images and a concurrent parity judgement task of a series of digits. To investigate the attentional maintenance processes, we manipulated the cognitive load (CL) of the concurrent task. CL effect is typically interpreted as the involvement of attentional maintenance processes. The task was adapted to each participant according to their processing speed and memory span. As expected, the results showed higher recall performance in healthy controls compared with post-stroke patients. Consistent with the literature, we also observed higher performance when the CL was low compared with high. However, the improvement in recall at low CL was smaller for post-stroke patients compared with controls, suggesting that post-stroke WM deficit could be in part due to a deficit of the attentional maintenance processes.  相似文献   
30.
S mith G. J. W., R uuth E., F ranzén G. & S jöholm L. Intermittent regressions in a serial afterimage experiment as signs of schizophrenia. Scand. J. Psychol ., 1972 , 13 , 27 33.—A group of 35 young patients suspected of schizophrenia were tested in a serial afterimage (AI) experiment and were also rated on the Rockland-Pollin scale. Subjects with high psychotic scores showed one or more regressions to immature (size-constant, positive, physiognomic) images in their Al serials, images typical of children who cannot clearly distinguish their Ails as subjective phenomena distinct from the outside world. The Al test thus indicates schizophrenics to be characterized by intermittent withdrawal into a world of experiencing the self and non-self as not clearly distinguished. Regressions were rare in two control groups.  相似文献   
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