Nonparametric inference in nonlinear principal components analysis: Exploration and beyond

In the social and behavioral sciences, data sets often do not meet the assumptions of traditional analysis methods. Therefore, nonlinear alternatives to traditional methods have been developed. This thesis starts with a didactic discussion of nonlinear principal components analysis (NLPCA), illustrated by an application considering caregiver-child interactions in day-care. Traditional PCA explores data structures, summarizing the observed information in underlying variables, called principal components. The method only gives a sensible solution if the variables are numeric, and linearly related to each other. NLPCA is developed for situations in which these assumptions do not apply. It incorporates different types of variables (nominal, ordinal, and numeric) and discovers and handles nonlinear relationships. As PCA does not make assumptions about variable distributions, it does not seem theoretically sensible to apply standard (asymptotic) formulas for statistical inference. Therefore, this thesis shows easily applicable ways of assessing stability and statistical significance of the elements of the NLPCA solution (eigenvalues, component loadings, component scores, category quantifications) without making prior assumptions about the data (i.e., nonparametrically), using the bootstrap and permutation tests, respectively. By providing relatively simple inferential measures for NLPCA, a wider use of this method in the psychological and educational context may be promoted

What about the children?: Co-occurrence of child maltreatment and parental separation

Education and Child Studie

Rebutting existing misconceptions about multiple imputation as a method for handling missing data

Missing data is a problem that occurs frequently in many scientific areas. The most sophisticatedmethod for dealing with this problem is multiple imputation. Contrary to other methods, like listwise deletion, this method does not throw away information, and partly repairs the problem ofsystematic dropout. Although from a theoretical point of view multiple imputation is consideredto be the optimal method, many applied researchers are reluctant to use it because of persistentmisconceptions about this method. Instead of providing an(other) overview of missing data methods, or extensively explaining how multiple imputation works, this article aims specifically atrebutting these misconceptions, and provides applied researchers with practical arguments supporting them in the use of multiple imputation.Multivariate analysis of psychological dat

NPM-2017: nationale prevalentiestudie mishandeling van kinderen en jeugdigen

Development Psychopathology in context: famil

Young children's cortisol levels at out-of-home child care: a meta-analysis

Education and Child StudiesEducation and Child Studie

The Five Factor Model of personality and evaluation of drug consumption risk

The problem of evaluating an individual's risk of drug consumption and misuse is highly important. An online survey methodology was employed to collect data including Big Five personality traits (NEO-FFI-R), impulsivity (BIS-11), sensation seeking (ImpSS), and demographic information. The data set contained information on the consumption of 18 central nervous system psychoactive drugs. Correlation analysis demonstrated the existence of groups of drugs with strongly correlated consumption patterns. Three correlation pleiades were identified, named by the central drug in the pleiade: ecstasy, heroin, and benzodiazepines pleiades. An exhaustive search was performed to select the most effective subset of input features and data mining methods to classify users and non-users for each drug and pleiad. A number of classification methods were employed (decision tree, random forest, $k$-nearest neighbors, linear discriminant analysis, Gaussian mixture, probability density function estimation, logistic regression and na{\"i}ve Bayes) and the most effective classifier was selected for each drug. The quality of classification was surprisingly high with sensitivity and specificity (evaluated by leave-one-out cross-validation) being greater than 70\% for almost all classification tasks. The best results with sensitivity and specificity being greater than 75\% were achieved for cannabis, crack, ecstasy, legal highs, LSD, and volatile substance abuse (VSA).Comment: Significantly extended report with 67 pages, 27 tables, 21 figure

Parent-child agreement on parent-to-child maltreatment

FSW - Self-regulation models for health behavior and psychopathology - ou

Estimating the Heritability of Experiencing Child Maltreatment in an Extended Family Design

Child-driven genetic factors can contribute to negative parenting and may increase the risk of being maltreated. Experiencing childhood maltreatment may be partly heritable, but results of twin studies are mixed. In the current study, we used a cross-sectional extended family design to estimate genetic and environmental effects on experiencing child maltreatment. The sample consisted of 395 individuals (225 women; M age = 38.85 years, rangeage = 7–88 years) from 63 families with two or three participating generations. Participants were oversampled for experienced maltreatment. Self-reported experienced child maltreatment was measured using a questionnaire assessing physical and emotional abuse, and physical and emotional neglect. All maltreatment phenotypes were partly heritable with percentages for h 2 ranging from 30% (SE = 13%) for neglect to 62% (SE = 19%) for severe physical abuse. Common environmental effects (c 2) explained a statistically significant proportion of variance for all phenotypes except for the experience of severe physical abuse (c 2 = 9%, SE = 13%, p = .26). The genetic correlation between abuse and neglect was ρg = .73 (p = .02). Common environmental variance increased as socioeconomic status (SES) decreased (p = .05), but additive genetic and unique environmental variances were constant across different levels of SES

Efficacy of the video-feedback intervention to promote positive parenting and sensitive discipline in twin families (VIPP-Twins): Study protocol for a randomized controlled trial

Development Psychopathology in context: famil