ABSTRACT Planned missingness in commonly administered proportions of LibQUAL+® and Lite instrumen... more ABSTRACT Planned missingness in commonly administered proportions of LibQUAL+® and Lite instruments may lead to loss of information. Data from three previous administrations of LibQUAL+® protocol were used to simulate data representing five proportions of administration. Statistics of interest (i.e., means, adequacy and superiority gaps, standard deviations, and Pearson and polychoric correlations) and their confidence intervals (CIs) from simulated and real data were compared. All CIs for the statistics of interest for simulated data contained the original values. Root mean squared errors, and absolute and relative biases showed that accuracy in the estimates decreased with increase in Lite proportion. The recommendation is to administer the Lite version to not more than 20% of the respondents if the purpose of the data collection is to conduct any inferential analysis. If researchers are interested in calculating means alone, up to 80% Lite version may be used to capture the true values adequately. However, standard deviations need to be interpreted to understand the quality of the means. Loss of accuracy in estimates may be compounded in analyses that use at least two statistics of interest.
ABSTRACT LibQUAL+® is an instrument purported to measure three dimensions of library service qual... more ABSTRACT LibQUAL+® is an instrument purported to measure three dimensions of library service quality: service affect, library as a place, and information control. After changes were made to the instrument in 2003, however, no confirmatory factor analyses have been published in peer-reviewed journals affirming the three-factor structure of LibQUAL+®. These deficiencies were addressed by testing the hypothesized three-factor structure and the stability of that structure over time. Specifically, data from three samples (n = 550; n = 3261; n = 2103) were collected over a five-year period and analyzed using a multi-group confirmatory factor analysis. Results suggest that the theoretical model fit the data across the three samples and demonstrates factorial invariance over time. Multicollinearity between affect of service and information control, however, indicate that service quality may be measured as two dimensions rather than three, providing a more parsimonious explanation of service quality.
ABSTRACT The most recent development in the field of Item Response Theory (IRT) has been the eval... more ABSTRACT The most recent development in the field of Item Response Theory (IRT) has been the evaluation of IRT models as multilevel models, known as Multilevel IRT models (MLIRT). These models offer several statistical and practical advantages over ordinary IRT models. However, models such as 2-PL MLIRT models have not been studied yet. This dissertation consists of two studies, a simulation and a substantiation for an urban school district dataset. The simulation study tested the performance of twoparameter (2-PL) MLIRT models with predictor variables under various conditions that included 3 test lengths (15, 30, and 60 items), 4 sample sizes (200, 500, 1000, and 2000), 2 correlation conditions between the predictor variable and the ability (or attitude) parameter (rpb=.35 and .8), and 4 binomial distributions of the predictor variable (p=0.1, 0.25, 0.4, and 0.5). The bias and Root Mean Square Deviation (RMSD) values of the item parameters indicated that the distribution of the predictor variable and the correlation between the predictor and the ability (or attitude) parameter did not affect the estimates of 2-PL MLIRT models. These models performed well for sample sizes as low as 500 and test lengths as low as 15 which is lower than the required sample size for ordinary IRT models. Even for a sample size of 200, sufficiently accurate estimates were obtained with more than 300 iterations. The second study investigated the characteristics of the items that measured urban teachers’ perceptions of cultural awareness and beliefs about teaching African American children and tested whether these perceptions were influenced by the teachers’ gender, ethnicity, or teaching experience. Teacher beliefs about teaching African American students, culturally responsive management, and cultural awareness factors were influenced by the ethnicity of the teachers. Culturally responsive management, home and community support, and curriculum and instructional strategies factors were influenced by the teaching experience of the teachers. Items that were biased based on ethnicity or teaching experience were identified. None of the items exhibited gender bias. The study identified items that could be used over other items when the need for a shorter instrument or more informative categories arises.
International Journal of Electronic Commerce, 2010
This study examined channel-migration behavior using a decomposed Theory of Planned Behavior with... more This study examined channel-migration behavior using a decomposed Theory of Planned Behavior with crossover effects in brick-and-mortar stores and the Internet. An online survey was administered at four research sites (N= 547) and factor analysis and structural equation modeling, with multigroup analysis, were utilized for data analysis. Hedonic beliefs did not influence either of the channels, whereas, utilitarian beliefs were significant predictors in both brick-and-mortar stores and the Internet. Additionally, ...
ABSTRACT Planned missingness in commonly administered proportions of LibQUAL+® and Lite instrumen... more ABSTRACT Planned missingness in commonly administered proportions of LibQUAL+® and Lite instruments may lead to loss of information. Data from three previous administrations of LibQUAL+® protocol were used to simulate data representing five proportions of administration. Statistics of interest (i.e., means, adequacy and superiority gaps, standard deviations, and Pearson and polychoric correlations) and their confidence intervals (CIs) from simulated and real data were compared. All CIs for the statistics of interest for simulated data contained the original values. Root mean squared errors, and absolute and relative biases showed that accuracy in the estimates decreased with increase in Lite proportion. The recommendation is to administer the Lite version to not more than 20% of the respondents if the purpose of the data collection is to conduct any inferential analysis. If researchers are interested in calculating means alone, up to 80% Lite version may be used to capture the true values adequately. However, standard deviations need to be interpreted to understand the quality of the means. Loss of accuracy in estimates may be compounded in analyses that use at least two statistics of interest.
ABSTRACT LibQUAL+® is an instrument purported to measure three dimensions of library service qual... more ABSTRACT LibQUAL+® is an instrument purported to measure three dimensions of library service quality: service affect, library as a place, and information control. After changes were made to the instrument in 2003, however, no confirmatory factor analyses have been published in peer-reviewed journals affirming the three-factor structure of LibQUAL+®. These deficiencies were addressed by testing the hypothesized three-factor structure and the stability of that structure over time. Specifically, data from three samples (n = 550; n = 3261; n = 2103) were collected over a five-year period and analyzed using a multi-group confirmatory factor analysis. Results suggest that the theoretical model fit the data across the three samples and demonstrates factorial invariance over time. Multicollinearity between affect of service and information control, however, indicate that service quality may be measured as two dimensions rather than three, providing a more parsimonious explanation of service quality.
ABSTRACT The most recent development in the field of Item Response Theory (IRT) has been the eval... more ABSTRACT The most recent development in the field of Item Response Theory (IRT) has been the evaluation of IRT models as multilevel models, known as Multilevel IRT models (MLIRT). These models offer several statistical and practical advantages over ordinary IRT models. However, models such as 2-PL MLIRT models have not been studied yet. This dissertation consists of two studies, a simulation and a substantiation for an urban school district dataset. The simulation study tested the performance of twoparameter (2-PL) MLIRT models with predictor variables under various conditions that included 3 test lengths (15, 30, and 60 items), 4 sample sizes (200, 500, 1000, and 2000), 2 correlation conditions between the predictor variable and the ability (or attitude) parameter (rpb=.35 and .8), and 4 binomial distributions of the predictor variable (p=0.1, 0.25, 0.4, and 0.5). The bias and Root Mean Square Deviation (RMSD) values of the item parameters indicated that the distribution of the predictor variable and the correlation between the predictor and the ability (or attitude) parameter did not affect the estimates of 2-PL MLIRT models. These models performed well for sample sizes as low as 500 and test lengths as low as 15 which is lower than the required sample size for ordinary IRT models. Even for a sample size of 200, sufficiently accurate estimates were obtained with more than 300 iterations. The second study investigated the characteristics of the items that measured urban teachers’ perceptions of cultural awareness and beliefs about teaching African American children and tested whether these perceptions were influenced by the teachers’ gender, ethnicity, or teaching experience. Teacher beliefs about teaching African American students, culturally responsive management, and cultural awareness factors were influenced by the ethnicity of the teachers. Culturally responsive management, home and community support, and curriculum and instructional strategies factors were influenced by the teaching experience of the teachers. Items that were biased based on ethnicity or teaching experience were identified. None of the items exhibited gender bias. The study identified items that could be used over other items when the need for a shorter instrument or more informative categories arises.
International Journal of Electronic Commerce, 2010
This study examined channel-migration behavior using a decomposed Theory of Planned Behavior with... more This study examined channel-migration behavior using a decomposed Theory of Planned Behavior with crossover effects in brick-and-mortar stores and the Internet. An online survey was administered at four research sites (N= 547) and factor analysis and structural equation modeling, with multigroup analysis, were utilized for data analysis. Hedonic beliefs did not influence either of the channels, whereas, utilitarian beliefs were significant predictors in both brick-and-mortar stores and the Internet. Additionally, ...
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Papers by Prathiba Natesan