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Multiple-factor analysis : its purpose and meaningHellyer, Sydney January 1950 (has links)
The purpose of the present study was that of presenting the fundamental theorems and techniques of Thurstone's Multiple-Factor Analysis in a manner that would be understandable to the non-mathematically trained student of psychology.
The work was introduced by a discussion of Spearman's "Theory of Two Factors" which is so-called since the method analyses each test into a general factor "g" and a specific factor. It was found that such a factorization could be performed if the correlation matrix exhibited hierarchical order. The tetrad difference equation and a standard error formula were next discussed as tests of this order. Finally, mention was made of a few of the problems which investigators have attempted to solve by means of the method.
Upon turning attention to the multiple-factor theory, an initial chapter was devoted to the presentation of the relationship between such theory and scientific method in general. This facilitated a discussion of some of the major limitations and values of the technique. It was found that the methods could best be designated as classificatory. Furthermore, it was discovered that factor analysis was not only applicable to a diversity of problems in psychology but also to those of other sciences.
Following this more general discussion, consideration was given to the derivation of the fundamental equations. It was proven that if the original scores are converted to standard form the sum of the squares of the factor loadings for any test is equal to unity. It was also shown that each factor loading for statistically independent factors is the square root of the variance that is attributable to that factor. The fundamental theorem of factor analysis, which proves that any reduced correlation matrix can be factorized, was then discussed since it is basic to the entire theory.
The centroid method of factoring a reduced correlation matrix was next developed. A method was thus obtained by which the correlation matrix could be analysed into a common factor matrix. However, since Thurstone does not consider these to be psychologically meaningful factors it was found that a rotation of reference frame must then be carried out.
Consideration was given to the problem of rotating axes and a method examined which enables one to rotate axes in a two-dimensional plot. This method was found to be such that it could be generalized to an r dimensional factor pattern. It had the advantage of furnishing a graphic record of the relationships among the tests. However, it had a disadvantage in that many diagrams must be plotted if the number of dimensions is large.
Upon examining the problem of attaching psychological meaning to the factors, it was noted that subjectivity must play a large part and so no rote rules could be furnished as a solution to this problem. For this reason several examples of interpretations were presented in order to enable the reader to obtain a clearer insight into the logical steps employed.
Finally, the limitations of this study were considered and a brief discussion of the possible future development of factor analysis was presented. / Arts, Faculty of / Psychology, Department of / Graduate
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A comparative study of iterative and noniterative factor analytic techniques in small to moderate sample sizes /Brewer, Carl G. January 1986 (has links)
No description available.
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Study of degradation of chlorophylls using DAD-HPLC and chemometricsKavianpour, Keyhandokht January 1998 (has links)
No description available.
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Testing the factor proportions theory in a multi-factor world : the case of Hong Kong.January 1984 (has links)
by Cheung Chun Keung, Edwin. / Bibliography: leaves 76-79 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1984
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Self-efficacy Theory: Relevance of General and Specific Efficacy Beliefs for Psychosocial Adaptation to Chronic Illness Over TimeRapley, Patrica January 2001 (has links)
Over the last decade or more, chronic illness research has consistently found that the lineaer relationship between knowledge and behaviour or between behaviour change and improved health outcomes does not exist. Furthermore, the link between behaviour and health status is not as strong as the link between illness-specific efficacy belier and health status. Strategies to increase confidence in illness-specific behaviours have gradually assumed more importance in improving health outcomes. Strategies to improve behaviour-specific efficacy belief can assist individuals to change their behaviour by influencing behavioural choices, effort and persistence with task man demands. Concomitantly, it has been suggested that there is a positive relationship between efficacy belief and psychosocial functioning. It is unclear as to whether this empirical evidence also applies to chronic illness conditions with a complex self-care regimen. The degree to which a more general level of confidence, or efficacy belief, can also contribute to psychosocial functioning is unknown. The focus of this study was to examine the relative impact of general and illness-specific efficacy expectations on psychosocial adaptation to illness over nine months. The study measured illness-specific efficacy beliefs when it was expected that they were still developing. / The illness-specific beliefs were compared to the purportedly more stable general efficacy belief. This longitudinal study employed an exploratory predictive design to measure efficacy beliefs in the natural setting. Data were collected at entry to the study, at three and nine months Participants included adults from three chronic illness groups: Arthritis (n= = ), diabetes type 1 (n = 104) and type 2 (n = 122). The self-report questionnaires used collect the data were three illness-specific efficacy belief measures, general self-efficacy and the Psychosocial Adjustment to Illness Scale. The dependent variable of interest was psychosocial adaptation to illness. Multiple regression analysis provided evidence of between-group differences in the positive contribution of general and illness-specific efficacy beliefs to psychosocial adaptation for chronic illness groups with different regimen attributes. The variables best able to predict psychosocial adaptation to illness over time, after being adjusted for perceived level of stress and general self-efficacy (belief in abilities in general), were illness-specific efficacy beliefs. A general efficacy belief contributed to the illness adaptation process initially but its influence reduced as the influence of illness-specific beliefs increased. Repeated measures MANOVA confirmed the stability of general efficacy belief. The contribution of this study to current knowledge of self- -efficacy theory is its application to self-management programs for chronic illness groups. The findings suggest that the more stable general efficacy belief has a role in psychosocial adaptation to chronic illness during the period when illness-specific efficacy beliefs, targeted by self-management programs, are still developing.
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A factor model of urban aerosol pollution : a new method of source identification /Henry, Ronald Claude. January 1977 (has links)
Thesis (Ph. D.)--Oregon Graduate Center, 1977.
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Three Essays on Spectral Analysis and Dynamic FactorsLiska, Roman 10 September 2008 (has links)
The main objective of this work is to propose new procedures for the general dynamic factor analysis
introduced by Forni et al. (2000). First, we develop an identification method for determining the number of common shocks in the general dynamic factor model. Sufficient conditions for consistency of the criterion are provided for large n (number of series) and T (the series length). We believe that our procedure can shed
light on the ongoing debate on the number of factors driving the US or Eurozone economy. Second, we show how the dynamic factor analysis method proposed in Forni et al. (2000), combined with our identification method, allows for identifying and estimating joint and block-specific common factors. This leads to a more
sophisticated analysis of the structures of dynamic interrelations within and between the blocks in suchdatasets.
Besides the framework of the general dynamic factor model we also propose a consistent lag window spectral density estimator based on multivariate M-estimators by Maronna (1976) when the underlying data are coming from the alpha mixing stationary Gaussian process.
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noneTsai, Fang-mei 15 July 2005 (has links)
none
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Bidrag till språkfaktorernas psykologiDahlgren, Olov. January 1947 (has links)
Akademisk avhandling--Göteborgs högskola. / Extra t.p., with thesis note, inserted. "Literatureförteckning": p. [264]-281.
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The interrelationship among hyperactivity, defiance and emotional disorder /Kam, Siu-yee, Josephine. January 1989 (has links)
Thesis (M. Soc. Sc.)--University of Hong Kong, 1989.
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