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Social and Behavioral Sciences Commons™
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Full-Text Articles in Social and Behavioral Sciences
Logistic Regression Under Sparse Data Conditions, David A. Walker, Thomas J. Smith
Logistic Regression Under Sparse Data Conditions, David A. Walker, Thomas J. Smith
Journal of Modern Applied Statistical Methods
The impact of sparse data conditions was examined among one or more predictor variables in logistic regression and assessed the effectiveness of the Firth (1993) procedure in reducing potential parameter estimation bias. Results indicated sparseness in binary predictors introduces bias that is substantial with small sample sizes, and the Firth procedure can effectively correct this bias.
A Comparison Of Methods For Longitudinal Analysis With Missing Data, James Algina, H. J. Keselman
A Comparison Of Methods For Longitudinal Analysis With Missing Data, James Algina, H. J. Keselman
Journal of Modern Applied Statistical Methods
In a longitudinal two-group randomized trials design, also referred to as randomized parallel-groups design or split-plot repeated measures design, the important hypothesis of interest is whether there are differential rates of change over time, that is, whether there is a group by time interaction. Several analytic methods have been presented in the literature for testing this important hypothesis when data are incomplete. We studied these methods for the case in which the missing data pattern is non-monotone. In agreement with earlier work on monotone missing data patterns, our results on bias, sampling variability, Type I error and power support the …