In the present study teacher students' contextual learning experiences were examined longitudinally in authentic study environments using the contextual activity sampling system, a means of mobile-supported experience sampling. The students' (n = 9) experiences were first recorded during a 2 week period in their first year of study. The same…

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides nutritious foods that promote the health of low-income pregnant women, new mothers, infants, and preschool children. This study examines WIC participation dynamics of infants and children from 2001 to 2003 using the Survey of Income and Program Participation…

The purposes of this study are: (1) to demonstrate the superiority of simple ridge regression over ordinary least squares regression through theoretical argument and empirical example; (2) to modify ridge regression through use of the variance normalization criterion; and (3) to demonstrate the superiority of simple ridge regression based on the…

Conceptual rationales from five research contexts are presented, which all posit unmeasured variables that interact with observed independent variables to produce a complete model of the dependent variable. Strategies for overcoming related difficulties are outlined, including increased longitudinal assessment, oversampling of levels of…

A statistical method has been developed for nested incomplete samples in a longitudinal study in which part of the sample has dropped out in such a way that the data have a nested pattern. A procedure which performed well in a Monte Carlo experiment was extended to a two-factor incomplete design with repeated measures on one factor. Methods…