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11.
Alwin Stegeman 《Psychometrika》2007,72(4):601-619
The Candecomp/Parafac (CP) method decomposes a three-way array into a prespecified number R of rank-1 arrays, by minimizing the sum of squares of the residual array. The practical use of CP is sometimes complicated
by the occurrence of so-called degenerate sequences of solutions, in which several rank-1 arrays become highly correlated
in all three modes and some elements of the rank-1 arrays become arbitrarily large. We consider the real-valued CP decomposition
of all known three-sliced arrays, i.e., of size p×q×3, with a two-valued typical rank. These are the 5×3×3 and 8×4×3 arrays, and the 3×3×4 and 3×3×5 arrays with symmetric 3×3
slices. In the latter two cases, CP is equivalent to the Indscal model. For a typical rank of {m,m+1}, we consider the CP decomposition with R=m of an array of rank m+1. We show that (in most cases) the CP objective function does not have a minimum but an infimum. Moreover, any sequence
of feasible CP solutions in which the objective value approaches the infimum will become degenerate. We use the tools developed
in Stegeman (2006), who considers p×p×2 arrays, and present a framework of analysis which is of use to the future study of CP degeneracy related to a two-valued
typical rank. Moreover, our examples show that CP uniqueness is not necessary for degenerate solutions to occur.
The author is supported by the Dutch Organisation for Scientific Research (NWO), VENI grant 451-04-102. 相似文献
12.
Patrick Chiroro Tendayi G. Viki Ann Frodi Tinashe Muromo Alwin Tsigah 《Journal of Psychology in Africa》2013,23(1):17-26
The study investigated the nature and prevalence of self-reported childhood sexual abuse (CSA) among a sample of Zimbabwean girls and college students. A total of 1059 high school girls and college students with a mean age (M = 18.31, SD = 3.66) participated in study. Overall, a CSA prevalence rate of 41.26% was found. The highest CSA prevalence rate was found among respondents who resided on commercial farms and mines (53%). Respondents who lived with their biological parents during childhood were significantly less likely to be sexually abused than were respondents who lived with non-parents such as uncles and brothers-in-law. Only 7.22% of the perpetrators were strangers. This study shows that sexual abuse of children in Zimbabwe is rampant, multifaceted, and linked to cultural factors that must be addressed as part of efforts to confront this scourge. 相似文献
13.
Alwin Diemer 《Man and World》1974,7(4):323-352
Ohne Zusammenfassung 相似文献
14.
A wandering mind is not always a creative mind. Anecdotes about ideas spontaneously entering awareness during walks, showers, and other off-task activities are plenty. The science behind it, however, is still inconclusive. Creativity might result from how thought context—whether thoughts are on-task or off-task—relates to thought dynamics—how thoughts unfold. To explore this, study 1 (n = 85) surveyed creative professionals about a single idea they had earlier in the day. The spontaneity of thoughts positively correlated with self-reported creativity, whereas off-task thoughts or doing something else did not. Study 2 (n = 180) replicated these findings in a student sample during an idea generation task and added that free movement of thoughts also correlates with self-reported originality during idea generation. As indicated by expert ratings, no relationship of thought dynamics and thought context was found with population-level creativity. Herewith, this study suggests that thought dynamics, rather than thought context, explain the often suggested relationship between mind wandering and creativity. 相似文献
15.
The CANDECOMP/PARAFAC (CP) model decomposes a three-way array into a prespecified number of R factors and a residual array by minimizing the sum of squares of the latter. It is well known that an optimal solution for
CP need not exist. We show that if an optimal CP solution does not exist, then any sequence of CP factors monotonically decreasing
the CP criterion value to its infimum will exhibit the features of a so-called “degeneracy”. That is, the parameter matrices
become nearly rank deficient and the Euclidean norm of some factors tends to infinity. We also show that the CP criterion
function does attain its infimum if one of the parameter matrices is constrained to be column-wise orthonormal. 相似文献
16.
Iris A. M. Smits Marieke E. Timmerman Alwin Stegeman 《The British journal of mathematical and statistical psychology》2016,69(2):105-121
Maximum likelihood estimation of the linear factor model for continuous items assumes normally distributed item scores. We consider deviations from normality by means of a skew‐normally distributed factor model or a quadratic factor model. We show that the item distributions under a skew‐normal factor are equivalent to those under a quadratic model up to third‐order moments. The reverse only holds if the quadratic loadings are equal to each other and within certain bounds. We illustrate that observed data which follow any skew‐normal factor model can be so well approximated with the quadratic factor model that the models are empirically indistinguishable, and that the reverse does not hold in general. The choice between the two models to account for deviations of normality is illustrated by an empirical example from clinical psychology. 相似文献
17.
Craig S. Cashwell J. Scott Young Jodi L. Tangen Amber L. Pope Alwin Wagener Hallie Sylvestro Robert A. Henson 《Counseling and values》2016,61(2):159-175
Many clients bring a belief in God or a Higher Power into counseling sessions. What is less clear, however, is how counselors conceptualize “god,” which may affect how spirituality is integrated in the counseling process. To explore this question, the authors conducted a concept map study of god images among counseling students. Results suggest that students harbor broad and diverse conceptualizations of god, which may affect the counseling process. 相似文献
18.
The present paper examines claims of a growing cultural divide in the United States. We analyze social change in beliefs about gender over a period of 36 years (from 1974 to 2010) in the United States using data from the nationally representative General Social Survey (GSS). We find evidence of growing gender egalitarianism until the mid-1990s, with a reversal between 1996 and 2000, and a decline in state differences in beliefs about gender over time in our decomposition analysis and multilevel models. Although we find significant differences in gender beliefs among states in the 1970s based on their voting record on the Equal Rights Amendment and based on patterns of family formation and family life associated with the Second Demographic Transition, these differences among states decreased or disappeared entirely by the early years of the twenty-first century. We highlight the implications of our findings for the ongoing public and academic debate surrounding growing cultural differences among states. 相似文献
19.
The presence of random measurement error in indicators of theoretical constructs biases observed estimates of relations among those constructs. Correcting for this bias is particularly important when random measurement error is substantial, or is substantially different for indicators of distinct constructs included in a theoretical model. Validity assessment in the case of thematic apperceptive measures of the achievement motive (TAT n Achievement) has been vulnerable to interpretive errors because these indicators of the achievement motive are typically much less reliable than indicators of other constructs to which the motive may be related, and no correction has been made for the bias introduced by such differential measurement error. Here we illustrate a causal modeling approach to validity assessment for TAT n Achievement that incorporates explicit true-score measurement models of theoretical constructs. We confirm the hypothesis that the achievement motive construct is positively related to work satisfaction in a representative sample of adult males in the United States, taken in 1976 (N = 413). Evidence for the discriminant validity of story content versus story length, an issue raised in the literature on the TAT, is also presented in this nomological network. 相似文献