"Growth mixture models" (GMMs) with nonignorable missing data have drawn increasing attention in research communities but have not been fully studied. The goal of this article is to propose and to evaluate a Bayesian method to estimate the GMMs with latent class dependent missing data. An extended GMM is first presented in which class…

Verbal ability comprises receptive (understanding) and active (producing) facets. While the first (e.g. as literacy in PIRLS and PISA) is frequently analyzed in its relationship to further cognitive abilities and parental attributes the latter is rarely investigated. The present study using data from N=280 students aged 9 to 14 years investigated…

The aim of the present study was to investigate whether temperament and cognitive abilities are related to recognition performance of Caucasian and African faces and of a nonfacial stimulus class, Greebles. Seventy Caucasian infants were tested at 3 months with a habituation/dishabituation paradigm and their temperament and cognitive abilities…

Systematic errors are often unavoidable in the introductory physics laboratory. As has been demonstrated in many papers in this journal, such errors can present a fundamental problem for data analysis, particularly when comparing the data to a given model. In this paper I give three examples in which my students use popular curve-fitting software…

This essay examines the stages of inquiry when we seek to formulate quality of life in an era before our own. There arises the question of the extent to which today's formulation of quality of life can be applied to an era far removed from our own. Implicitly, there is the nature of the time interval, T[subscript 1]...T[subscript n], and the…

With disasters on the rise, counselors need to increase their cultural awareness, knowledge, and skills to work with affected communities. This study reports outcomes of a four-week immersion experience in southern Africa with six counselor-trainees. Data sources for this qualitative study were: daily journals and demographic forms. Outcomes…

In this study, eight English professors thought aloud as they read four lyric poems and composed a short text proposing a hypothetical talk about them for a professional conference. The study used a crossed design in which participants read a poem in each of the following conditions: familiar to them and close to their professional writing,…

Several psycholinguistic theories have appealed to the linguistic notion of markedness to help explain asymmetrical patterns of behavioural data. We suggest that this sort of markedness is best thought of as a derived rather than a primitive notion, emerging when the distributional properties of linguistic categories interact with general-purpose…

In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

Whether schools have productive data-analysis sessions leading to instructional improvements and increased student learning or meetings that are a waste of time and resources could well hinge on the structures that are put in place by and the expectations of school and district leadership. Based on his work as a data coach with more than 200…

This work investigates how vowel duration and vowel quality affect degrees of vowel-to-vowel coarticulation. The effects of these two factors on vowel-to-vowel coarticulation have previously received little study. Phonological durational differences due to vowel length distinction were examined in Thai. It was hypothesized that shorter vowel…

It's not exactly a well-kept secret: Despite the drumbeat for data that has echoed through the jungles of education for over a decade, its nuanced use to make decisions for students is rare. And even though state and national longitudinal data initiatives from the US Department of Education (ED) have increased the pressure, relatively few schools…

Ramsay-curve item response theory (RC-IRT) is a nonparametric procedure that estimates the latent trait using splines, and no distributional assumption about the latent trait is required. For item parameters of the two-parameter logistic (2-PL), three-parameter logistic (3-PL), and polytomous IRT models, RC-IRT can provide more accurate estimates…

This paper presents categorical data that were gathered at two urban clinics and two suburban clinics of Johns Hopkins in an effort to identify characteristics of young female patients who successfully complete the three-injection sequence of the Gardasil quadrivalent human papillomavirus vaccine (HPV4). Available categorical correlates included…

Many educational policymakers consider attendance as a tool to induce learning. Researchers also agree that attendance has a positive effect on learning; however, there are few empirical studies that measure the nature and significance of that effect. The authors analyzed the effect of class attendance on academic performance and evaluated the…