Feeding and attachment in infants with and without orofacial clefts

Do the many feeding problems associated with isolated cleft palate (CP) and cleft lip and palate (CLP) adversely affect the emotional bond between mother and infant? This question was addressed by observing the feeding interactions of 126 mother-infant pairs (57 infants with CLP or CP) at 3 and 12 months of age. Infants with CLP were found to be less communicative during feeding at 3 month than comparison group infants. However, by 12 months, the CLP group had improved to a level indistinguishable from the CP and comparison groups. This change was unrelated to the timing of cleft palate surgery. Although maternal sensitivity during feeding at 3 months did not predict the attachment quality of infants with clefts, maternal sensitivity at 12 months was concurrently related to attachment. Change in maternal sensitivity between 3 and 12 months was also predictive of attachment in the cleft groups, with mothers of avoidant infants showing greater attenuation in maternal sensitivity than the mothers of secure infants.     

When does inconsistency hurt? On the relation between phonological consistency effects and the reliability of sublexical units

Phonological consistency describes to what extent a letter string in one word is pronounced equally in other words. Phonological reliability describes to what extent a sublexical unit is usually consistent throughout a language. The relationship between the two concepts was investigated by comparing five sublexical units (onset-consonants, vowel, end-consonants, and the concatenation of the vowel with begin- or end-consonants) in Dutch and English with respect to their reliability and to how their consistency was related to naming errors and latencies. In a regression analysis, naming latencies and errors on genuine Dutch words (consistent) and imported words (inconsistent) were predicted by the phonological consistency of the five units. The same was done for two sets of English naming data. Consistency had a much stronger effect in Dutch than in English naming studies when all five units were considered. The special role of the vowel plus end-consonants, which has been found in English naming data, could not be demonstrated in Dutch. In both languages, the size of consistency effects mirrors the reliability of the five units.     

Measurement of Ability in Adaptive Learning and Assessment Systems when Learners Use On-Demand Hints

Adaptive learning and assessment systems support learners in acquiring knowledge and skills in a particular domain. The learners’ progress is monitored through them solving items matching their level and aiming at specific learning goals. Scaffolding and providing learners with hints are powerful tools in helping the learning process. One way of introducing hints is to make hint use the choice of the student. When the learner is certain of their response, they answer without hints, but if the learner is not certain or does not know how to approach the item they can request a hint. We develop measurement models for applications where such on-demand hints are available. Such models take into account that hint use may be informative of ability, but at the same time may be influenced by other individual characteristics. Two modeling strategies are considered: (1) The measurement model is based on a scoring rule for ability which includes both response accuracy and hint use. (2) The choice to use hints and response accuracy conditional on this choice are modeled jointly using Item Response Tree models. The properties of different models and their implications are discussed. An application to data from Duolingo, an adaptive language learning system, is presented. Here, the best model is the scoring-rule-based model with full credit for correct responses without hints, partial credit for correct responses with hints, and no credit for all incorrect responses. The second dimension in the model accounts for the individual differences in the tendency to use hints.     

A MCMC-method for models with continuous latent responses

This paper introduces a new technique for estimating the parameters of models with continuous latent data. Using the Rasch model as an example, it is shown that existing Bayesian techniques for parameter estimation, such as the Gibbs sampler, are not always easy to implement. Then, a new sampling-based Bayesian technique, called the DA-T-Gibbs sampler, is introduced. The DA-T-Gibbs sampler relies on the particular latent data structure of latent response models to simplify the computations involved in parameter estimation. This research was supported by the Dutch National Research Council (NWO) (grant number 575-30-001).     

Adaptation of the Mullen Scales of Early Learning for use among infants aged 5‐ to 24‐months in rural Gambia

Infants in low‐resource settings are at heightened risk for compromised cognitive development due to a multitude of environmental insults in their surroundings. However, the onset of adverse outcomes and trajectory of cognitive development in these settings is not well understood. The aims of the present study were to adapt the Mullen Scales of Early Learning (MSEL) for use with infants in a rural area of The Gambia, to examine cognitive development in the first 24‐months of life and to assess the association between cognitive performance and physical growth. In Phase 1 of this study, the adapted MSEL was tested on 52 infants aged 9‐ to 24‐months (some of whom were tested longitudinally at two time points). Further optimization and training were undertaken and Phase 2 of the study was conducted, where the original measures were administered to 119 newly recruited infants aged 5‐ to 24‐months. Infant length, weight and head circumference were measured concurrently in both phases. Participants from both phases were split into age categories of 5–9 m (N = 32), 10–14 m (N = 92), 15–19 m (N = 53) and 20–24 m (N = 43) and performance was compared across age groups. From the ages of 10–14 m, Gambian infants obtained lower MSEL scores than US norms. Performance decreased with age and was lowest in the 20–24 m old group. Differential onsets of reduced performance were observed in the individual MSEL domains, with declines in visual perception and motor performance detected as early as at 10–14 months, while reduced language scores became evident after 15–19 months of age. Performance on the MSEL was significantly associated with measures of growth.     

A Note on “Constant Latent Odds-Ratios Models and the Mantel–Haenszel Null Hypothesis” Hessen, 2005

In a recent paper, Hessen (Psychometrika 70(3):497–516, 2005) introduces the class of constant latent odds-ratios models as an extension of the Rasch model for which the sum score is still the sufficient statistic for ability. In this paper the relation between both the general and the general parametric constant latent odds-ratios model and the Rasch model is considered.     

Dynamic estimation in the extended marginal Rasch model with an application to mathematical computer-adaptive practice

We introduce a general response model that allows for several simple restrictions, resulting in other models such as the extended Rasch model. For the extended Rasch model, a dynamic Bayesian estimation procedure is provided, which is able to deal with data sets that change over time, and possibly include many missing values. To ensure comparability over time, a data augmentation method is used, which provides an augmented person-by-item data matrix and reproduces the sufficient statistics of the complete data matrix. Hence, longitudinal comparisons can be easily made based on simple summaries, such as proportion correct, sum score, etc. As an illustration of the method, an example is provided using data from a computer-adaptive practice mathematical environment.     

The Prevention of Suicidal Behaviors: An Overview

The authors discuss the development of the concept of prevention as it has evolved from the public health and mental health fields. Concepts of epidemiology, treatment, and community mental health are defined in terms of their contributions to the evolution of prevention thinking. Four models of prevention are presented and critiqued: the public health model, the operational model, the antecedent conditions model, and the injury control model. Essential ingredients for implementing effective preventive interventions are presented, as well as examples of practical preventive interventions.     

Employment Status and Sex Role Attitudes in Middle-class Suburban Mothers

Twenty-one employed and 31 nonemployed suburban mothers of 2nd and 6th grade children were administered the Bern Sex Role Inventory (BSRI), Welledey Role Orientation Scale (WROS), and items from the Traditional Family Inventory (TFI items). Employed mothers agreed with more nontraditional attitudes on the WROS and described themselves in more masculine or androgynous terms than did nonempldyed mothers. These differences were not affected by grade or sex of child. While the directionality of effect could not be established, it was clear that these employed women viewed themselves and their roles as wives and mothers differently than did their nonemployed counterparts. This was true despite differences in conditions of employment, and despite a more traditional overall attitude among these women than has been reported in studies using younger, upper middle-class university women. In this study, mothers employed part time were more traditional in their responses to TFI items concerned with child rearing attitudes than were mothers employed full time. Again, while directionality of effect could not be established, the decision to work part time and thus spend more time with the children is compatible with a more traditional attitude. The usefulness of these easily administered measures in dividing groups of women for further research on sex roles outside university communities is apparent.     

Probability matrix decomposition models

In this paper, we consider a class of models for two-way matrices with binary entries of 0 and 1. First, we considerBoolean matrix decomposition, conceptualize it as alatent response model (LRM) and, by making use of this conceptualization, generalize it to a larger class of matrix decomposition models. Second,probability matrix decomposition (PMD) models are introduced as a probabilistic version of this larger class of deterministic matrix decomposition models. Third, an algorithm for the computation of the maximum likelihood (ML) and the maximum a posteriori (MAP) estimates of the parameters of PMD models is presented. This algorithm is an EM-algorithm, and is a special case of a more general algorithm that can be used for the whole class of LRMs. And fourth, as an example, a PMD model is applied to data on decision making in psychiatric diagnosis. This paper is based on a chapter of the first author's doctoral dissertation, written at the University of Leuven and supervised by Paul De Boeck.