Diagnosing Global Case Influence on MAR Versus MNAR Model Comparisons

When missingness is suspected to be not at random (MNAR) in longitudinal studies, researchers sometimes compare the fit of a target model that assumes missingness at random (here termed a MAR model) and a model that accommodates a hypothesized MNAR missingness mechanism (here termed a MNAR model). It is well known that such comparisons are only interpretable conditional on the validity of the chosen MNAR model’s assumptions about the missingness mechanism. For that reason, researchers often perform a sensitivity analysis comparing the MAR model to not one, but several, plausible alternative MNAR models. In the social sciences, it is not widely known that such model comparisons can be particularly sensitive to case influence, such that conclusions drawn could depend on a single case. This article describes two convenient diagnostics suited for detecting case influence on MAR–MNAR model comparisons. Both diagnostics require much less computational burden than global influence diagnostics that have been used in other disciplines for MNAR sensitivity analyses. We illustrate the interpretation and implementation of these diagnostics with simulated and empirical latent growth modeling examples. It is hoped that this article increases awareness of the potential for case influence on MAR–MNAR model comparisons and how it could be detected in longitudinal social science applications.     

Modeling Ability Differentiation in the Second-Order Factor Model

In this article we present factor models to test for ability differentiation. Ability differentiation predicts that the size of IQ subtest correlations decreases as a function of the general intelligence factor. In the Schmid–Leiman decomposition of the second-order factor model, we model differentiation by introducing heteroscedastic residuals, nonlinear factor loadings, and a skew-normal second-order factor distribution. Using marginal maximum likelihood, we fit this model to Spanish standardization data of the Wechsler Adult Intelligence Scale (3rd ed.) to test the differentiation hypothesis.     

Fitting Nonlinear Latent Growth Curve Models With Individually Varying Time Points

Individual growth trajectories of psychological phenomena are often theorized to be nonlinear. Additionally, individuals’ measurement schedules might be unique. In a structural equation framework, latent growth curve model (LGM) applications typically have either (a) modeled nonlinearity assuming some degree of balance in measurement schedules, or (b) accommodated truly individually varying time points, assuming linear growth. This article describes how to fit 4 popular nonlinear LGMs (polynomial, shape-factor, piecewise, and structured latent curve) with truly individually varying time points, via a definition variable approach. The extension is straightforward for certain nonlinear LGMs (e.g., polynomial and structured latent curve) but in the case of shape-factor LGMs requires a reexpression of the model, and in the case of piecewise LGMs requires introduction of a general framework for imparting piecewise structure, along with tools for its automation. All 4 nonlinear LGMs with individually varying time scores are demonstrated using an empirical example on infant weight, and software syntax is provided. The discussion highlights some advantages of modeling nonlinear growth within structural equation versus multilevel frameworks, when time scores individually vary.     

SERVING AND LEARNING ATA UNIVERSITY LABORATORY SCHOOL: STUDENTS FROM BIRTH THOUGH ADULTHOOD BENEFIT WHEN SERVICE LEARNING IS INTEGRATED INTO THE PRESERVICE CURRICULUM

Service‐Learning (S‐L) pedagogy is attracting increased attention in teacher education. This article describes the implementation of S‐L in the preservice early childhood curriculum, which placed students in a birth‐5 years setting. It identifies a continuum of learning to care, which begins in infancy, as caring capacities emerge, through to adulthood, when preservice teachers learn from experienced mentors how caring characterizes their interactions with learners of all ages. Students’ journals indicate they believe S‐L experiences contribute to their personal, academic and professional development. Carefully implemented S‐L experiences validate students’ caring interactions, give them first‐hand experiences with young children during which they can apply theoretical constructs, provide experiences which help them clarify their own career goals, and make them feel better prepared to manage instructional and classroom management dimensions of working with young children.     

Dutch Dyslexia in Adulthood: Core Features and Variety

This study aimed to explore how alphabetic readers learn to read Chinese. First-year Chinese beginning learners who are skilled English readers were tested for their sensitivity to the visual-orthographic structures of Chinese characters. The study also explored the effect of the frequency of the characters in their curriculum on performance of a lexical decision and naming task. The students' linguistic knowledge about the characters was also tested. Results showed that the beginning learners were sensitive to the structural complexity of characters, they accepted simple characters more quickly and more accurately than compound characters, and they responded faster and more accurately to high-frequency than to low-frequency characters. Sensitivity to the structural composition of the character was also revealed: The learners rejected noncharacters containing illegal radical forms faster and more accurately than those containing legal radical forms in illegal positions, which in turn were rejected faster and more accurately than those containing legal radical forms in legal positions. A significant frequency effect was also found in the naming task, though the effect of structural complexity was not significant. These results suggest that perceptual learning plays an important role in early nonalphabetic learning by alphabetic readers. Both cross-writing system differences and second-language status may have an impact on such learning.     

Reading Comprehension Tests Vary in the Skills They Assess: Differential Dependence on Decoding and Oral Comprehension

Comprehension tests are often used interchangeably, suggesting an implicit assumption that they are all measuring the same thing. We examine the validity of this assumption by comparing some of the most popular reading comprehension measures used in research and clinical practice in the United States: the Gray Oral Reading Test (GORT), the two assessments (retellings and comprehension questions) from the Qualitative Reading Inventory (QRI), the Woodcock–Johnson Passage Comprehension subtest (WJPC), and the Reading Comprehension test from the Peabody Individual Achievement Test (PIAT). Modest intercorrelations among the tests suggested that they were measuring different skills. Regression analyses showed that decoding, not listening comprehension, accounts for most of the variance in both the PIAT and the WJPC; the reverse holds for the GORT and both QRI measures. Large developmental differences in what the tests measure were found for the PIAT and the WJPC, but not the other tests, both when development was measured by chronological age and by word reading ability. We discuss the serious implications for research and clinical practice of having different comprehension tests measure different skills and of having the same test assess different skills depending on developmental level.     

Greetings from the Editor

The eight early childhood educators who participated in this study were admitted into a 60-credit statewide distance-delivered Associate of Applied Science (AAS) degree program at the University of Alaska. All eight educators were women of Alaska Native ancestry who lived and worked in remote and rural Native communities. Seven of these teachers were employed by Head Start programs and one taught preschool for a rural school district. A major goal of the statewide distance-delivered AAS program is that participants will become skilled observers of children and learn to use observation to make decisions that foster developmentally appropriate and culturally responsive services. All the course work in our AAS degree program involves actively doing and using observations of children. This study is based on a principle that intrinsic changes can occur in program management, curriculum development, and teacher practice when teachers learn how to use observation of children rather than external evaluation to make decisions about their programs.