1,720,958 research outputs found
The Compound Stimuli Visual Information (CSVI) task revisited: presentation time, probability distributions, and attentional capacity limits
No full textThis study examined the validity of the Bose-Einstein (B-E) model of the Compound Stimuli Visual Information (CSVI) task, and its assumptions. Two experiments compared adults’ performance on the CSVI task in standard (5 sec) presentation condition and with shorter presentation times. Individual participants’ performance was analyzed with the B-E model, with different assumptions on the number of attending acts in each condition. Both experiments found that the capacity limit estimates found in both conditions were highly correlated with each other, and their means did not differ. The goodness of fit of B-E distributions to the data was also tested. It is concluded that the B-E model provides a valid estimate of attentional capacity limits in the CSVI
Validazione di un modello probabilistico degli span complessi basato sulla Theory of Constructive Operators
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A reappraisal of the Bose-Einstein model of the CSVI task: New experimental data, replications, and implications
No full textIn a seminal, often-cited and often-misunderstood article, Pascual-Leone (1970) proposed his view of a domain-general, capacity-limited attentional resource (M capacity) as a main factor of cognitive development and intelligence, and presented the Compound Stimuli Visual Information (CSVI) task, along with its Bose-Einstein (B-E) performance model, as a method to assess M capacity. Some aspects of the CSVI and its B-E model were questioned: long stimulus exposure could produce capacity over-estimates (Cowan, 2001); the assumptions on how many times a participant attends to a stimulus could be unwarranted; it would be desirable to assess the fit of B-E distributions with current methods, more refined than those used in the Seventies. This study re-examines the validity of the B-E model of the CSVI task, and its assumptions
Modelling Working Memory Capacity: Is the Magical Number Four, Seven, or Does it Depend on What You Are Counting?
No full textLimited attentional capacity is essential to working memory. How its limit should be assessed is a debated issue. Five experiments compare Cowan’s 4-units and Pascual-Leone’s 7-units models of limited working memory capacity, with presentation time and attention to operative schemes as potential explanations of this discrepancy. Experiments 1a–1c used the Compound Stimuli Visual Information (CSVI) task, with long versus brief presentation. Capacity was estimated with the Bose-Einstein model, assuming a different number of attending acts in each condition. Participants’ k estimates in both conditions were highly correlated and the means were not different, indicating that the same capacity is assessed in both conditions. Experiments 2 and 3 used the 5000-msec CSVI, and the Visual Array Task (VAT) in two conditions (5000- vs. 120-msec presentation). Capacity in the VAT was estimated with Morey’s Bayesian method. Participants’ k estimates in both VAT conditions were correlated, but the mean was higher with long presentation, suggesting that the long condition benefits from recoding or chunking. The k estimate in the CSVI correlated with the short VAT and (to a lesser degree in Exp.2) with the long VAT. The mean estimate of k in the CSVI was one unit more than in the short VAT. We conclude that the CSVI and the short VAT tap the same capacity, one unit of which in the short VAT is allocated to an operative scheme; we discuss how Cowan’s and Pascual-Leone’s views on limited capacity can be reconcile
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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