Predicting early educational program placement with discrete discriminant analysis

The purpose of this study was to predict placement and nonplacement outcomes for mildly handicapped three through five year old children given knowledge of developmental screening test data. Discrete discriminant analysis (Anderson, 1951; Cochran & Hopkins, 1961; Goldstein & Dillon, 1978) was used to classify children into either a placement or nonplacement group using developmental information retrieved from longitudinal Child Find records (1982-89). These records were located at the Florida Diagnostic and Learning Resource System (FDLRS) in Sarasota, Florida and provided usable data for 602 children. The developmental variables included performance on screening test activities from the Comprehensive Identification Process (Zehrbach, 1975), and consisted of: (a) gross motor skills, (b) expressive language skills, and (c) social-emotional skills. These three dichotomously scored developmental variables generated eight mutually exclusive and exhaustive combinations of screening data. Combined with one of three different types of cost-of-misclassification functions, each child in a random cross-validation sample of 100 was classified into one of the two outcome groups minimizing the expected cost of misclassification based on the remaining 502 children. For each cost function designed by the researchers a comparison was made between classifications from the discrete discriminant analysis procedure and actual placement outcomes for the 100 children. A logit analysis and a standard discriminant analysis were likewise conducted using the 502 children and compared with results of the discrete discriminant analysis for selected cost functions.     

Analyzing multiple end points with a two-stage design in clinical trials

In many clinical trials, the assessment of the response to interventions can include a large variety of outcome variables which are generally correlated. The use of multiple significance tests is likely to increase the chance of detecting a difference in at least one of the outcomes between two treatments. Furthermore, univariate tests do not take into account the correlation structure. A new test is proposed that uses information from the interim analysis in a two-stage design to form the rejection region boundaries at the second stage. Initially, the test uses Hotelling’s T² at the end of the first stage allowing only, for early acceptance of the null hypothesis and an O’Brien ‘type’ procedure at the end of the second stage. This test allows one to ‘cheat’ and look at the data at the interim analysis to form rejection regions at the second stage, provided one uses the correct distribution of the final test statistic. This distribution is derived and the power of the new test is compared to the power of three common procedures for testing multiple outcomes: Bonferroni’s inequality, Hotelling’s T²and O’Brien’s test. O’Brien’s test has the best power to detect a difference when the outcomes are thought to be affected in exactly the same direction and the same magnitude or in exactly the same relative effects as those proposed prior to data collection. However, the statistic is not robust to deviations in the alternative parameters proposed a priori, especially for correlated outcomes. The proposed new statistic and the derivation of its distribution allows investigators to consider information from the first stage of a two-stage design and consequently base the final test on the direction observed at the first stage or modify the statistic if the direction differs significantly from what was expected a prior.     

The Common Factors Model: Its Place in Clinical Practice and Research

The common factors model advances the view that client, relationship, and clinician factors account for a greater proportion of therapeutic change than do specific techniques or types of therapy. In this era of evidence-based practice, in which specific techniques are heavily emphasized, this updated review of the common factors model focuses attention on other components of therapeutic change, including the client's contribution, the therapeutic alliance, and clinician factors. The common factors model has recent and long-standing research support of several kinds. The model affirms many widely used therapeutic practices and has led to the development of several procedures to enhance therapeutic outcomes. This article explores the origins and development of the common factors model; its current research support; and its implications for practice, research, and education.     

The differential role of human capital and health in explaining welfare exit‐route and labour outcomes

The aim of this study was to determine the differential effects of human capital and health on welfare exit‐route, earnings and working hours among female welfare recipients in Israel. The study also examined whether higher human capital mediates the effect of health problems on the different outcomes. The data were obtained from a national panel survey of 2,700 single mothers who were receiving welfare when the Israeli welfare reform was implemented. The effect of health was found to be more consistent than the effect of human capital. Formal education had no effect on welfare exit‐route, while health did. The effect of health on working hours was more profound than the effect of human capital, while the reverse applied to earnings. Richer human capital did not mediate the effect of health problems. These findings suggest that the prediction power of human capital on labour and welfare decisions has weakened under welfare reform provision.     

Parents' perceptions of contact with the Norwegian Child Welfare Services

Listening to the opinions of service users is important in research. This study explored how parents cognitively and emotionally perceive contact with the Norwegian Child Welfare Services (CWS). It also compared the reports of parents recently referred to the CWS with reports of more experienced users. A content analysis was conducted on open‐ended survey responses from parents (n = 697). This study fills a gap in the literature on how parents perceive contact with the CWS and what they see as important factors when judging this contact. The findings showed that 40.6% of the parents reported exclusively positive experiences, 30.7% of the parents reported solely negative experiences, while 24% of the parents described both positive and negative experiences. The content of the positive and negative experiences were related to characteristics of the child welfare workers, the quality of the relationship, the help offered and the parent's feelings of insecurity and fear. New CWS users tended to view the contact as more positive than the more experienced ones. Practical implications are presented.     

Dynamic latent trait models with mixed hidden Markov structure for mixed longitudinal outcomes

We propose a general Bayesian joint modeling approach to model mixed longitudinal outcomes from the exponential family for taking into account any differential misclassification that may exist among categorical outcomes. Under this framework, outcomes observed without measurement error are related to latent trait variables through generalized linear mixed effect models. The misclassified outcomes are related to the latent class variables, which represent unobserved real states, using mixed hidden Markov models (MHMMs). In addition to enabling the estimation of parameters in prevalence, transition and misclassification probabilities, MHMMs capture cluster level heterogeneity. A transition modeling structure allows the latent trait and latent class variables to depend on observed predictors at the same time period and also on latent trait and latent class variables at previous time periods for each individual. Simulation studies are conducted to make comparisons with traditional models in order to illustrate the gains from the proposed approach. The new approach is applied to data from the Southern California Children Health Study to jointly model questionnaire-based asthma state and multiple lung function measurements in order to gain better insight about the underlying biological mechanism that governs the inter-relationship between asthma state and lung function development.     

Potential Climate Change Health Risks from Increases in Heat Waves: Abnormal Birth Outcomes and Adverse Maternal Health Conditions

We investigate the risks presented by heat waves for adverse health conditions for babies and expectant mothers when these mothers have been exposed to heat waves during gestation or during the period just prior to conception. Rather than just birth weight and gestational age, we focus on less common metrics such as abnormal conditions in the newborn (fetal distress, reliance on a ventilator, and meconium aspiration) and adverse health conditions in the mother (pregnancy‐related hypertension, uterine bleeding during pregnancy, eclampsia, and incompetent cervix). We use monthly panel data for over 3,000 U.S. counties, constructed from the confidential version of the U.S. Natality Files for 1989–2008. Our models control for sociodemographic factors and include county, month, and state‐by‐year fixed effects to control for unobserved spatial and timewise heterogeneity in the data. Even within the United States, where there is widespread access to air conditioning, heat waves increase the fraction of babies with abnormal conditions related to maternal stress, as well as the fraction of mothers who experience pregnancy‐related adverse health conditions. The scope for these risks in developing countries is likely to be even greater.     

Paved with Good Intentions: The Pathway to Adoption and the Costs of Delay

The thrust of UK adoption policy is to promote adoption as thebest route to a stable family life for children in the caresystem unable to return to their birth families. However, whatwe know about outcomes for adopted children comes mainly fromstudies that report on children already in placement. This articlereports on the findings of a study that examined the outcomesof a complete sample of 130 older looked after children whohad all been the subject of an adoption best interest decision.Many were successfully placed but, of those who were not, thestudy was able to identify factors that influenced placementoutcome. The negative impact on placement outcomes and the increasedfinancial costs of poor assessment and delays in planning andaction are highlighted in this paper. The reasons why delaysoccurred, the costs of those delays and the impact on childoutcomes lend support to recent government attempts to reducedelay by the introduction of timescales into the adoption process.     

Research Review: Young people leaving care

This paper reviews the international research on young people leaving care. Set in the context of a social exclusion framework, it explores young people’s accelerated and compressed transitions to adulthood, and discusses the development and classification of leaving care services in responding to their needs. It then considers the evidence from outcome studies and argues that adopting a resilience framework suggests that young people leaving care may fall into three groups: young people ‘moving on’, ‘survivors’ and ‘victims’. In concluding, it argues that these three pathways are associated with the quality of care young people receive, their transitions from care and the support they receive after care.     

非英语专业大学生词汇学习策略的研究

词汇学习是英语学习的重要内容之一。近年来,有关词汇学习策略的研究在二语习得领域中受到广泛重视。在前人研究的基础上,笔者策划了对大学非英语专业二年级326名文理科及艺术类学生词汇学习策略的实证研究。本文运用定量分析的方法,对非英语专业学生所使用的词汇学习策略以及它们和词汇测试成绩之间的关系进行了讨论和分析,并对大学英语的词汇教学提出几点建议。