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1.
The power of the chi-square test statistic used in structural equation modeling decreases as the absolute value of excess kurtosis of the observed data increases. Excess kurtosis is more likely the smaller the number of item response categories. As a result, fit is likely to improve as the number of item response categories decreases, regardless of the true underlying factor structure or χ2-based fit index used to examine model fit. Equivalently, given a target value of approximate fit (e.g., root mean square error of approximation ≤ .05) a model with more factors is needed to reach it as the number of categories increases. This is true regardless of whether the data are treated as continuous (common factor analysis) or as discrete (ordinal factor analysis). We recommend using a large number of response alternatives (≥ 5) to increase the power to detect incorrect substantive models.  相似文献   

2.
This article is an elaboration on the use of the binomial test of model fit value, which in this article will be referred to as the binomial index of model fit value, to gauge the degree that the data fit a path analytic or structural equation model. In addition, this article responds to the criticisms and comments made by Hsu (this issue), Drezner and Drezner (this issue), and Raykov and Penev (this issue) regarding the use of this approach to measuring the degree of model fit. We appreciate the comments provided by these authors. Their comments have assisted us in clarifying our reason for developing the binomial index of model fit procedure as well as our perception of its use.  相似文献   

3.
Parental involvement is well documented as a significant contributor to the self‐efficacy and academic achievement of students. A structural equation model of parent involvement with family socioeconomic status, student gender, parents’ aspirations for their children, mathematics efficacy, and mathematics achievement was tested to examine whether parent involvement in the 10th grade remains relevant to achievement. A sample of data pertaining to 8,673 10th graders from the Educational Longitudinal Study was analyzed. The results indicated that the fit of the measurement model to the data was good (χ2 = 3081.62, df = 87, p = .0, normed fit index [NFI] = .96, comparative fit index [CFI] = .96, root mean square error of approximation [RMSEA] = .064), as was the structural model (χ2 = 3470.69, df = 94, p = .00, NFI = .96, CFI = .96, RMSEA = .065). Although the effect was small in magnitude, parent involvement in advising had a significant indirect relationship with mathematics achievement via mathematics efficacy of 10th graders.  相似文献   

4.
Marsh and Balla (1986) and Marsh, Balla, and McDonald (1988) proposed an index of fit called χ2I2, but McDonald and Marsh (1990) subsequently demonstrated that the index is biased and recommended that it not be used. Bollen (1989) independently proposed Δ2 which is the same as χ2I2 (hereafter referred to as χ2I2‐Δ2), indicating that it adjusts for sample size and degrees of freedom (df). Gerbing and Anderson (1992), apparently based on the assumption that the χ2I2‐Δ2 index is unbiased and appropriately corrects for df (penalizes a lack of parsimony), recommended its use, and the index is routinely presented by major computer programs (e.g., EQS and LISREL 8). However, a more critical evaluation of the χ2I2‐Δ2 index reveals that: (a) it is systematically biased (i.e., its value varies systematically with N) although the size of the bias may be small; (b) the adjustment for df is inappropriate in that it penalizes model parsimony instead of model complexity; and (c) the inappropriate penalty for model parsimony is larger for small N. Because of these undesirable properties, the χ2I2‐Δ2 index is not recommended for routine use.  相似文献   

5.
The goal of this study was to investigate the usefulness of person‐fit analysis in validating student score inferences in a cognitive diagnostic assessment. In this study, a two‐stage procedure was used to evaluate person fit for a diagnostic test in the domain of statistical hypothesis testing. In the first stage, the person‐fit statistic, the hierarchy consistency index (HCI; Cui, 2007 ; Cui & Leighton, 2009 ), was used to identify the misfitting student item‐score vectors. In the second stage, students’ verbal reports were collected to provide additional information about students’ response processes so as to reveal the actual causes of misfits. This two‐stage procedure helped to identify the misfits of item‐score vectors to the cognitive model used in the design and analysis of the diagnostic test, and to discover the reasons of misfits so that students’ problem‐solving strategies were better understood and their performances were interpreted in a more meaningful way.  相似文献   

6.
In this study we examined procedures for assessing model-data fit of item response theory (IRT) models for mixed format data. The model fit indices used in this study include PARSCALE's G2 , Orlando and Thissen's S − X2 and S − G2 , and Stone's χ2* and G2* . To investigate the relative performance of the fit statistics at the item level, we conducted two simulation studies: Type I error and power studies. We evaluated the performance of the item fit indices for various conditions of test length, sample size, and IRT models. Among the competing measures, the summed score-based indices S − X2 and S − G2 were found to be the sensible and efficient choice for assessing model fit for mixed format data. These indices performed well, particularly with short tests. The pseudo-observed score indices, χ2* and G2* , showed inflated Type I error rates in some simulation conditions. Consistent with the findings of current literature, the PARSCALE's G2 index was rarely useful, although it provided reasonable results for long tests.  相似文献   

7.
While morale among the elderly has been widely and extensively studied, results are varied and at times conflicting. Hence, the purpose of this study is to explore the factors affecting elderly morale of a select group of Filipinos in a community setting. A 64-item questionnaire was utilized to survey 323 Filipinos aged 60 and above residing in the National Capital Region of the Philippines in May 2013. Respondents completed a robotfoto, a checklist of chronic illnesses, and measures of the social support, functional ability, geriatric depression, and morale. Structural equation modeling was used to test the hypothesized model. Two competing models emerged in the study. Model 1 followed causal relationships indicated in the hypothesized model while model 2 considered modification indices that surfaced more acceptable fit indices (X2/df = 1.414, GFI [goodness of fit index] = 0.988, CFI [comparative fit index] = 0.987, RMSEA [root mean square error of approximation] = 0.036). Chronic illness, social support, and depression were found to be major predictors of morale. Number of chronic illnesses and depression were also found to have a negative relationship with functional ability, and chronic illness and social support were negatively correlated. Findings can assist health professionals such as nurses to identify the factors that shape elderly morale vis-a-vis the use of effective strategies that promote the well-being of elderly people. The emerging model can serve as reference to assess the effectiveness of quality of care rendered as manifested by morale.  相似文献   

8.
Orlando and Thissen's S‐X 2 item fit index has performed better than traditional item fit statistics such as Yen's Q1 and McKinley and Mill's G2 for dichotomous item response theory (IRT) models. This study extends the utility of S‐X 2 to polytomous IRT models, including the generalized partial credit model, partial credit model, and rating scale model. The performance of the generalized S‐X 2 in assessing item model fit was studied in terms of empirical Type I error rates and power and compared to G2. The results suggest that the generalized S‐X 2 is promising for polytomous items in educational and psychological testing programs.  相似文献   

9.
ABSTRACT

Language proficiency is highlighted in the literature on the adjustment and security of international students. India is the second top source country for mobile students globally, but few studies have focused explicitly on students from India. The purpose of this study was to examine the English language experiences of Indian students at New Zealand universities. This mixed-method study utilised a questionnaire (n?=?109) and interviews (n?=?15). Collectively the participants had high levels of confidence and proficiency in English language and adjusted more rapidly than many international students to the new academic environment. Major differences experienced by the participants between India and New Zealand related to unfamiliar forms of academic writing and tasks, and on the role of learning support services. Formal high value assessment was for some the first indication of a problem with writing. While most students adjusted through error-based learning others struggled with argumentation and avoiding plagiarism. These findings have relevance for local and international students. We recommend the use of, and research on, early low-stakes assessment of writing and on effective support services for students transitioning into new academic contexts.  相似文献   

10.
Given the relationships of item response theory (IRT) models to confirmatory factor analysis (CFA) models, IRT model misspecifications might be detectable through model fit indexes commonly used in categorical CFA. The purpose of this study is to investigate the sensitivity of weighted least squares with adjusted means and variance (WLSMV)-based root mean square error of approximation, comparative fit index, and Tucker–Lewis Index model fit indexes to IRT models that are misspecified due to local dependence (LD). It was found that WLSMV-based fit indexes have some functional relationships to parameter estimate bias in 2-parameter logistic models caused by violations of LD. Continued exploration into these functional relationships and development of LD-detection methods based on such relationships could hold much promise for providing IRT practitioners with global information on violations of local independence.  相似文献   

11.
Approximations to the distributions of goodness-of-fit indexes in structural equation modeling are derived with the assumption of multivariate normality and slight misspecification of models. The fit indexes considered in this article are Joreskog and Sorbom's goodness-of-fit index (GFI) and the adjusted GFI, McDonald's absolute GFI, Steiger and Lind's root mean squared error of approximation, Steiger's Γ1 and Γ2, Bentler and Bonett's normed fit index, Bollen's incremental fit index and ρ1, Tucker and Lewis's index ρ2, and Bentler's fit index (McDonald and Marsh's relative noncentrality index). An approximation to the asymptotic covariance matrix for the fit indexes is derived by using the delta method. Furthermore, approximations to the densities of the fit indexes are obtained from the transformations of the asymptotically noncentral chi-square distributed variable. A simulation is carried out to confirm the accuracy of the approximations.  相似文献   

12.
Individual person fit analyses provide important information regarding the validity of test score inferences for an individual test taker. In this study, we use data from an undergraduate statistics test (N = 1135) to illustrate a two-step method that researchers and practitioners can use to examine individual person fit. First, person fit is examined numerically with several indices based on the Rasch model (i.e., Infit, Outfit, and Between-Subset statistics). Second, person misfit is presented graphically with person response functions, and these person response functions are interpreted using a heuristic. Individual person fit analysis holds promise for improving score interpretation in that it may detect potential threats to validity of score inferences for some test takers. Individual person fit analysis may also highlight particular subsets of items (on which a test taker performs unexpectedly) that can be used to further contextualize her or his test performance.  相似文献   

13.
The purpose of this study was to design and validate an assessment tool to find out how primary school students perceive their competency-based learning. By examining the content validity (n = 35 experts), comprehension (n = 173 students) and construct (n = 523 students) of the instrument, the results showed correct psychometric quality, internal consistency, reliability and adequacy of the structural model: χ2/df = 2.08, TLI = 0.88, CFI = 0.90, GFI = 0.90, RMSEA = 0.04, and SRMR = 0.04. The final version of the Questionnaire on Perceived Competency-based Learning of primary school students (#ICOMpri1) includes eight dimensions and 27 items. The results showed a high perceived competency-based learning of primary school students. This is therefore a valid and reliable instrument that provides a more subjective and real vision of primary students’ academic performance. Nevertheless, future studies should analyse the criterion-related validity by comparing perception results with those of international academic achievement.  相似文献   

14.
The purpose of this study was to provide empirical evidence to support the validity of the Community of Inquiry (CoI) model survey. The participants for this study were undergraduate and graduate students (n = 1173) enrolled in fully online (57%) and blended online courses (43%) offered through WebCT during the spring 2008 semester at a mid-sized western university. One half of the student responses were randomly selected for exploratory factor analysis while the remaining half was subjected to confirmatory factor analysis. Results from the exploratory analysis identified a three factor model which was tested through confirmatory factor analysis and found to be an acceptable fit to the predicted population model. Results from this study suggest that the CoI survey holds promise as a useful evaluation tool for providing formative and summative feedback about the effectiveness of online courses and programs.  相似文献   

15.
This study examined the performance of 4 correlation-based fit indexes (marginal and conditional pseudo R 2s; average and conditional concordance correlations) in detecting misspecification in mean structures in growth curve models. Their performance was also compared to that of 4 traditional SEM fit indexes. We found that the marginal pseudo R 2 and average concordance correlation were able to detect misspecification in the marginal mean structure (average change trajectory). The conditional pseudo R 2 and concordance correlation could detect misspecification when it occurred in the conditional mean structure (individual change trajectory) or in both mean structures. Compared to the SEM fit indexes, the correlation-based fit indexes were more robust to sample size but were less robust to data properties such as magnitude of population mean and measurement error. Theoretical and practical implications of the results and directions for future research are discussed.  相似文献   

16.
Selecting a subset of predictors from a pool of potential predictors continues to be a common problem encountered by applied researchers in education. Because of several limitations associated with stepwise variable selection procedures, the examination of all possible regression solutions has been recommended. The authors evaluated the use of Mallow's Cp and Wherry's adjusted R 2 statistics to select a final model from a pool of model solutions. Neither the Cp nor the adjusted R 2 statistic correctly identified the underlying regression model any better and was generally worse than the stepwise selection method, which itself was poor. Using any of the model selection procedures studied here resulted in biased estimates of the authentic regression coefficients and underestimation of their standard errors. The use of theory and professional judgment is recommended for the selection of variables in a prediction equation.  相似文献   

17.
Research Findings: This study examined the contribution of teacher-student conflict at kindergarten to the child’s school adjustment in primary school using a Hong Kong sample. It investigated self-regulation as a mediator and parents’ positive relations with others as a moderator in that transition. At Time 1 (T1), kindergarten teachers reported their levels of conflict with individual children (N = 324, 168 girls), whereas children’s self-regulation was assessed with a Head-Toes-Knees-Shoulders Task. Fathers and mothers also rated their positive relations with others. At Time 2 (T2; 8 months later), when children were enrolled in primary school (N = 247, 126 girls), primary school teachers rated how well they adjusted to the new school. Moderated mediation analyses showed that although the direct effect of T1 teacher-student conflict on T2 school adjustment was not significant, the indirect effect of self-regulation was. T1 teacher-student conflicts were negatively related to children’s self-regulation, which in turn predicted subsequent school adjustment. Interestingly, this indirect effect was significant only when parents’ positive relations with others were low rather than high. Practice or Policy: The findings highlight the importance of both a warm and caring relationship in the home and self-regulation to successful school transition.  相似文献   

18.
Despite its importance to structural equation modeling, model evaluation remains underdeveloped in the Bayesian SEM framework. Posterior predictive p-values (PPP) and deviance information criteria (DIC) are now available in popular software for Bayesian model evaluation, but they remain underutilized. This is largely due to the lack of recommendations for their use. To address this problem, PPP and DIC were evaluated in a series of Monte Carlo simulation studies. The results show that both PPP and DIC are influenced by severity of model misspecification, sample size, model size, and choice of prior. The cutoffs PPP < 0.10 and ?DIC > 7 work best in the conditions and models tested here to maintain low false detection rates and misspecified model selection rates, respectively. The recommendations provided in this study will help researchers evaluate their models in a Bayesian SEM analysis and set the stage for future development and evaluation of Bayesian SEM fit indices.  相似文献   

19.
Conventionally, moderated mediation analysis is conducted through adding relevant interaction terms into a mediation model of interest. In this study, we illustrate how to conduct moderated mediation analysis by directly modeling the relation between the indirect effect components including a and b and the moderators, to permit easier specification and interpretation of moderated mediation. With this idea, we introduce a general moderated mediation model that can be used to model many different moderated mediation scenarios including the scenarios described in Preacher, Rucker, and Hayes (2007). Then we discuss how to estimate and test the conditional indirect effects and to test whether a mediation effect is moderated using Bayesian approaches. How to implement the estimation in both BUGS and Mplus is also discussed. Performance of Bayesian methods is evaluated and compared to that of frequentist methods including maximum likelihood (ML) with 1st-order and 2nd-order delta method standard errors and mL with bootstrap (percentile or bias-corrected confidence intervals) via a simulation study. The results show that Bayesian methods with diffuse (vague) priors implemented in both BUGS and Mplus yielded unbiased estimates, higher power than the ML methods with delta method standard errors, and the ML method with bootstrap percentile confidence intervals, and comparable power to the ML method with bootstrap bias-corrected confidence intervals. We also illustrate the application of these methods with the real data example used in Preacher et al. (2007). Advantages and limitations of applying Bayesian methods to moderated mediation analysis are also discussed.  相似文献   

20.
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