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| 2. |
- Yang-Wallentin, Fan, et al.
(författare)
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Non-linear structural equation modeling
- 2009
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Ingår i: Structural Equation Modeling in Educational Research. - Rotterdam : SensePublishers. - 9789087907877 - 9789087907884 ; , s. 317-328
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Research in the social sciences often includes hypotheses concerning interactive or nonlinear effects on a given outcome latent variable. When it comes to estimating such effects, however, there is lack of consensus on how to do so properly, particularly when performing structural equation modeling (SEM). A plethora of methods have been proposed and discussed, including those de-scribed in Algina and Moulder (2001), Jaccard and Wan (1995), Joreskog and yang (1996,1997), Yang-Jonsson (1997,1998), Klein and Moosbrugger (2000), Klein and Muthen (2002), Marsh,Wen, and Hau (2004), Ping (1996a, 1996b), Schumacker and Marcoulides (1998), and Wall and Amemiya (2001, 2003). Most approaches to latent variable interactions are based on a product indicator methodology originated by Kenny and Judd (1984) that requires a level of technical and computational sophistication that renders them quite inaccessible to the average practitioner. The focus of this chapter is on the discussion of a technically straightforward approach using latent variable scores to estimating interactive and nonlinear effects within SEM. The next section, we will first describe LVS approach in a theoretical framework and in succeeding section, the approach will demonstrate in a practical manner using an empirical data. To illustrate how latent variable scores can be used to estimate nonlinear relationship between latent variables we will use Reading comprehension model as an example.
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| 4. |
- Abramsson-Zetterberg, Lilianne, et al.
(författare)
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The impact of folate status and folic acid supplementation on the micronucleus frequency in human erythrocytes
- 2006
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Ingår i: Mutation Research. - : Elsevier BV. - 1383-5742 .- 1388-2139. ; 603:1, s. 33-40
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Tidskriftsartikel (refereegranskat)abstract
- Folic acid has a well-documented stabilising effect on chromosomes. A correlation between folate status and chromosome stability in humans has been reported in studies that were restricted to certain subpopulations, e.g., folate-deficient persons. The goal of the present investigation was to clarify if there also is a correlation between folate status and chromosome stability among individuals without any folate deficiency. The method used here is the recently developed flow cytometry-based micronucleus assay in human transferrin-positive reticulocytes (MN-Trf-Ret). In a blood sample, separation of the very young reticulocytes from the mature erythrocytes makes this micronucleus assay possible. This investigation comprises three studies (cross-sectional, giving baseline data), two of which are connected to an intervention study. In the three cross-sectional studies (total number of subjects, 99) the frequency of MN-Trf-Ret (fMN-Trf-Ret) was measured and compared with the serum folate status. In two of the studies also serum homocysteine and Vitamin B12 were measured and compared with the baseline fMN-Trf-Ret. Combining the results from the three cross-sectional studies, a negative correlation between folate status and fMN-Trf-Ret was obtained (p < 0.05). The goal of the intervention studies was to clarify if different nutritional supplementations had any effect on the fMN-Trf-Ret and the cell proliferation (percentage polychromatic erythrocytes, PCE). Each of the two studies involved two groups, one placebo and one supplemented group. In one of the studies the supplementation was folic acid, 1000 μg/day during 1 week (n = 30, both sexes); in the other intervention study, folic acid (800 μg/day), B12 (20 μg/day) and B6 (4 mg/day) were taken during 1 week (n = 29, both sexes). No significant difference in %PCE or fMN-Trf-Ret between the two groups was found in either of the two intervention studies.
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| 5. |
- Akrami, Nazar, et al.
(författare)
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Personality and Social Psychology Factors Explaining Sexism
- 2011
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Ingår i: Journal of Individual Differences. - : Hogrefe Publishing Group. - 1614-0001 .- 2151-2299. ; 32:3, s. 153-160
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Tidskriftsartikel (refereegranskat)abstract
- Previous research has almost exclusively examined sexism (negative attitudes toward women) from either a personality or a social-psychology perspective. In two studies (N = 379 and 182, respectively), we combine these perspectives and examine whether sexism is best explained by personality (Big-Five factors, social dominance orientation, and right-wing authoritarianism) or by social-psychological (group membership and group identification) variables - or by a combination of both approaches. Causal modeling and multiple regression analyses showed that, with the present set of variables, sexism was best explained by considering the combined influence of both personality- and social-psychology constructs. The findings imply that it is necessary to integrate various approaches to explain prejudice.
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| 6. |
- Andersson, Björn, 1984-
(författare)
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Contributions to Kernel Equating
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The statistical practice of equating is needed when scores on different versions of the same standardized test are to be compared. This thesis constitutes four contributions to the observed-score equating framework kernel equating.Paper I introduces the open source R package kequate which enables the equating of observed scores using the kernel method of test equating in all common equating designs. The package is designed for ease of use and integrates well with other packages. The equating methods non-equivalent groups with covariates and item response theory observed-score kernel equating are currently not available in any other software package.In paper II an alternative bandwidth selection method for the kernel method of test equating is proposed. The new method is designed for usage with non-smooth data such as when using the observed data directly, without pre-smoothing. In previously used bandwidth selection methods, the variability from the bandwidth selection was disregarded when calculating the asymptotic standard errors. Here, the bandwidth selection is accounted for and updated asymptotic standard error derivations are provided.Item response theory observed-score kernel equating for the non-equivalent groups with anchor test design is introduced in paper III. Multivariate observed-score kernel equating functions are defined and their asymptotic covariance matrices are derived. An empirical example in the form of a standardized achievement test is used and the item response theory methods are compared to previously used log-linear methods.In paper IV, Wald tests for equating differences in item response theory observed-score kernel equating are conducted using the results from paper III. Simulations are performed to evaluate the empirical significance level and power under different settings, showing that the Wald test is more powerful than the Hommel multiple hypothesis testing method. Data from a psychometric licensure test and a standardized achievement test are used to exemplify the hypothesis testing procedure. The results show that using the Wald test can provide different conclusions to using the Hommel procedure.
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| 7. |
- Andersson, Gustaf, et al.
(författare)
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Generalized Linear Factor Score Regression : A Comparison of Four Methods
- 2021
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Ingår i: Educational and Psychological Measurement. - : Sage Publications. - 0013-1644 .- 1552-3888. ; 81:4, s. 617-643
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Tidskriftsartikel (refereegranskat)abstract
- Factor score regression has recently received growing interest as an alternative for structural equation modeling. However, many applications are left without guidance because of the focus on normally distributed outcomes in the literature. We perform a simulation study to examine how a selection of factor scoring methods compare when estimating regression coefficients in generalized linear factor score regression. The current study evaluates the regression method and the correlation-preserving method as well as two sum score methods in ordinary, logistic, and Poisson factor score regression. Our results show that scoring method performance can differ notably across the considered regression models. In addition, the results indicate that the choice of scoring method can substantially influence research conclusions. The regression method generally performs the best in terms of coefficient and standard error bias, accuracy, and empirical Type I error rates. Moreover, the regression method and the correlation-preserving method mostly outperform the sum score methods.
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| 8. |
- Bali, Ranjula Swain, et al.
(författare)
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Achieving sustainable development goals: predicaments and strategies : Predicaments and Strategies
- 2020
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Ingår i: International Journal of Sustainable Development and World Ecology. - : Informa UK Limited. - 1745-2627 .- 1350-4509. ; 27:2, s. 96-106
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Tidskriftsartikel (refereegranskat)abstract
- The ambitious United Nations Sustainable Development Goals (SDGs) have been criticized for being universal, broadly framed, inconsistent and difficult to quantify, implement and monitor. We contribute by quantifying and prioritising the SDGs and their impact on sustainable development. We employ structural equation models (SEM) to investigate, which of the underlying pillars of SDGs (economic, social and environment) are the most effective in achieving sustainable development. Our results reveal that the developed countries benefit most by focusing on social and environmental factors, whereas the developing countries benefit most by retaining their focus on the economic and the social factors.
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| 9. |
- Bali, Ranjula Swain, et al.
(författare)
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COVID-19 Pandemic Waves: Identification and Interpretation of Global Data
- 2022
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The mention of the COVID-19 waves is as prevalent as the pandemic itself. We scientifically identify waves and the breaking points at which they begin and end from the beginning of the pandemic till June 2021. We use the Break Least Square method to determine the significance of COVID-19 waves for global-, regional-, and country-level data. The results show that the method works efficiently in detecting different breaking points. Identifying waves at the country level is more relevant than global or regional levels. Once it begins, and irrespective of the circumstances, the COVID-19 wave takes about 48 days on average to subside. Identifying the correct breaking points is critical to evaluate the impact of various COVID-19 variants and the different pharmaceutical and non-pharmaceutical interventions.
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| 10. |
- Bali Swain, Ranjula, et al.
(författare)
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Achieving Sustainable Development Goals : Predicaments and Strategies
- 2020
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Ingår i: International Journal of Sustainable Development and World Ecology. - : Taylor & Francis. - 1350-4509 .- 1745-2627. ; 27:2, s. 96-106
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Tidskriftsartikel (refereegranskat)abstract
- The ambitious United Nations Sustainable Development Goals (SDGs) have been criticized for being universal, broadly-framed, inconsistent and difficult to quantify, implement and monitor. We contribute by quantifying and prioritising the SDGs and their impact on sustainable development. We employ structural equation models (SEM) to investigate, which of the underlying pillars of SDGs (economic, social and environment) are the most effective in achieving sustainable development. Our results reveal that the developed countries, benefit most by focusing on social and environmental factors whereas the developing countries, benefit most by retaining their focus on the economic and the social factors.
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