Analysis of variance--why it is more important than ever

Analysis of variance (ANOVA) is an extremely important method in exploratory and confirmatory data analysis. Unfortunately, in complex problems (e.g., split-plot designs), it is not always easy to set up an appropriate ANOVA. We propose a hierarchical analysis that automatically gives the correct ANOVA comparisons even in complex scenarios. The inferences for all means and variances are performed under a model with a separate batch of effects for each row of the ANOVA table. We connect to classical ANOVA by working with finite-sample variance components: fixed and random effects models are characterized by inferences about existing levels of a factor and new levels, respectively. We also introduce a new graphical display showing inferences about the standard deviations of each batch of effects. We illustrate with two examples from our applied data analysis, first illustrating the usefulness of our hierarchical computations and displays, and second showing how the ideas of ANOVA are helpful in understanding a previously fit hierarchical model.Comment: This paper discussed in: [math.ST/0508526], [math.ST/0508527], [math.ST/0508528], [math.ST/0508529]. Rejoinder in [math.ST/0508530

Interviewer Effects on Nonresponse

In face-to-face surveys interviewers play a crucial role in making contact with and gaining cooperation from sample units. While some analyses investigate the influence of interviewers on nonresponse, they are typically restricted to single-country studies. However, interviewer training, contacting and cooperation strategies as well as survey climates may differ across countries. Combining call-record data from the European Social Survey (ESS) with data from a detailed interviewer questionnaire on attitudes and doorstep behavior we find systematic country differences in nonresponse processes, which can in part be explained by differences in interviewer characteristics, such as contacting strategies and avowed doorstep behavior.

Coverage Bias in European Telephone Surveys: Developments of Landline and Mobile Phone Coverage across Countries and over Time

With the decrease of landline phones in the last decade, telephone survey methodologists face a new challenge to overcome coverage bias. In this study we investigate coverage error for telephone surveys in Europe over time and compare two situations: classical surveys that rely on landline only with surveys that also include mobile phones. We analyzed Eurobarometer data, which are collected by means of face-to-face interviews and contain information on ownership of landline and mobile phones. We show that for the period 2000-2009, time has a significant effect on both mobile phone penetration and coverage bias. In addition, the countries’ development significantly affects the pace of these changes

Coverage Bias in European Telephone Surveys: Developments of Landline and Mobile Phone Coverage across Countries and over Time

With the decrease of landline phones in the last decade, telephone survey methodologists face a new challenge to overcome coverage bias. In this study we investigate coverage error for telephone surveys in Europe over time and compare two situations: classical surveys that rely on landline only with surveys that also include mobile phones. We analyzed Eurobarometer data, which are collected by means of face-to-face interviews and contain information on ownership of landline and mobile phones. We show that for the period 2000-2009, time has a significant effect on both mobile phone penetration and coverage bias. In addition, the countries’ development significantly affects the pace of these changes

International Nonresponse Trends across Countries and Years: An analysis of 36 years of Labour Force Survey data

Household survey nonresponse is a matter of concern in many countries. In one of the first international trend analyses, de Leeuw and de Heer (2002) found that response rates declined over the years, and that countries differed in response rates and nonresponse trends. Their analyses cover longitudinal data on the Labour Force Survey from National Statistical Institutes for the period 1980 to 1997. We added a new data set, covering the period 1998 -2015, and analysed nonresponse data over time and countries. In these analyses we differentiated between voluntary and mandatory surveys. The trends visible in de Leeuw and de Heer (2002) continue with possibly a small deceleration in refusal rates

Эффективность функционирования системы проката автомобилей в Крыму

Целью статьи является исследование роли проката автомобилей в развитии автомобильного туризма, анализ рынка проката в Крыму, определение проблем и направлений развития системы автопроката в Крыму

Reliability of the Dutch Pediatric Evaluation of Disability Inventory

Objective: To evaluate the reliability of the Dutch version of the Pediatric Evaluation of Disability Inventory (PEDI), an instrument for measuring functional status (capability and performance in self-care, mobility and social function) of young children using parent interviews. Design: Inter-interviewer reliability was studied after scoring audiotaped interviews by a second researcher. For test-retest reliability the same parent was interviewed twice within three weeks; in inter-respondent reliability both parents of a child were interviewed independently within a few days. On item level, percentage identical scores were computed, and on scale level intraclass correlation coef cients (ICC) and Cronbach's alphas were calculated. Subjects: Parents of 63 nondisabled and 53 disabled (various diagnosis) children aged between 7 and 88 months were interviewed. Results: On scale level, all ICCs were above 0.90 and Cronbach's alpha was 0.89 for the self-care domain, 0.74 for the mobility domain and 0.87 for the social function domain. On item level for the Functional Skills Scale, the mean percentage identical scores varied from 89 to 99, and for the Caregiver Assistance Scale from 54 to 90. Different scores between interviewers resulted partially from ambiguous interpretation of the item and/or the explanation. Conclusions: Although small adaptations have to be made, the psychometric properties of the Dutch PEDI are found to be good. 458 JE Wassenberg-Severijnen et al

Social network responses to victims of potentially traumatic events:A systematic review using qualitative evidence synthesis

BACKGROUND: A substantial number of qualitative studies examined how adult victims of potentially traumatic events (PTEs) experienced support provided by family members, friends, colleagues, and other significant others in the informal network. Importantly, the large majority of qualitative studies focused on the perceived support of victims of specific events such as sexual offences, partner violence, homicide, accidents and disasters. Although it is likely that across specific PTEs there are similarities as well as differences in experienced support from the informal network, to date no systematic review synthesized the results of qualitative studies on support from the informal network following various types of PTEs. The aim of the present systematic review is to fill this gap in the scientific knowledge, which is also highly relevant for victim services, policymakers, and the informal network. METHODS: A literature search of qualitative studies was conducted using the electronic databases of PubMed, Web of Science, CINAHL, Psych INFO, Scopus, Criminal Justice Abstracts and Picarta. The quality of the identified studies was assessed with the Consolidated Criteria for Reporting Qualitative research (COREQ) checklist, followed by analysis of the results of the identified studies using Qualitative Evidence Synthesis. FINDINGS: Seventy-five papers were included in the synthesis, involving 2799 victims of PTEs such as accidents, disasters, homicide, intimate partner violence (IPV), and sexual offences. Saturation was only achieved for IPV. Overall, four major categories of perceived social support were identified, namely, support perceived as supportive, supportive but insufficient, unsupportive, and absent from informal support providers, which included friends, family, neighbors, (if applicable) offender’s family, religious group members, work/school colleagues, fellow victims, the local community, and the social network in general. Across the PTE groups, there were similarities in experiencing positive forms of support (particularly empathy and sharing experiences) as well as negative forms of support (abandonment, avoidance, lack of empathy, and not experiencing support despite victim’s request for help). There were also differences across PTE groups, in particular, victims of sexual and intimate partner violence mentioned a number of other supportive (mobilizing support, no unsupportive responses) and non-supportive (e.g., justification or normalization of violence and minimizing responses) responses. CONCLUSIONS: The review showed that different actors within the social informal network can play an important role in providing support after victims experience violence, homicide, accidents, and disasters. However, the review revealed that the large majority of qualitative studies were aimed at victims of IPV, and only for this type of PTE was saturation achieved. This indicates that, although this synthesis identified several similarities and differences, it is still too early to draw more definitive conclusions on similarities and differences in experienced social support after various PTEs and that future qualitative studies focusing on other PTEs are much needed

Educational psychology in latin america: with linear hierarchical models

Research in clinical psychology, since its inception, has been aimed at analyzing, predicting and explaining the effect of treatments, by studying the change of patients in the course of them. To study the effects of therapy, research based on quantitative analysis models has historically used classical methods of parametric statistics, such as Pearson correlations, least squares regressions Student’s T-Tests and Variance Analysis (ANOVA). Hierarchical linear models (HLMs) represent a fundamental statistical strategy for research in psychotherapy, as they allow to overcome dependence on the observations usually presented in your data. The objective of this work is to present a guide to understanding, applying and reporting HLMs to study the effects of psychotherapy