Detecting early signs of autism is essential for timely diagnosis and initiation of effective interventions. Several research groups have initiated prospective studies of high-risk populations including infant siblings, to systematically collect data on early signs within a longitudinal design. Despite the potential advantages of prospective…

The research literature on screening and brief intervention (SBI) for unhealthy alcohol use is large and diverse. More than 50 clinical trials and 9 systematic reviews have been published on SBI in a range of healthcare settings, and via a variety of delivery approaches, in general practice, hospital wards, emergency departments, addiction…

The purpose of this ITEMS module is to provide an introduction to Markov chain Monte Carlo (MCMC) estimation for item response models. A brief description of Bayesian inference is followed by an overview of the various facets of MCMC algorithms, including discussion of prior specification, sampling procedures, and methods for evaluating chain…

The objective of this paper is to develop a brief screening instrument of posttraumatic stress disorder (PTSD) for young victims of natural disasters. Data were derived from flood victims in 1998 and 1999 in Hunan, China. A representative population sample of 6,852 subjects 7-15 years of age was selected. Among them, 6,073 (88.6%) were…

This chapter provides an overview of sampling methods that are appropriate for conducting online surveys. The authors review some of the basic concepts relevant to online survey sampling, present some probability and nonprobability techniques for selecting a sample, and briefly discuss sample size determination and nonresponse bias. Although some…

The Organisation for Economic Cooperation and Development's (OECD's) Programme for International Student Assessment (PISA) surveys, which take place every three years, have been designed to collect information about 15-year-old students in participating countries. PISA examines how well students are prepared to meet the challenges of the future,…

The Monitoring the Future study has provided the nation with a window into the important, but largely hidden, problem behaviors of illicit drug use, alcohol use, and tobacco use. It has provided a clearer view of the changing topography of these problems among adolescents and adults, a better understanding of the dynamics of factors that drive…

Purpose: Description of study participants and documentation of the desired diversity in the Prevention Research Centers Healthy Aging Research Network's Workgroup on Promoting Cognitive Health large multisite study designed to examine attitudes about brain health, behaviors associated with its maintenance, and information-receiving preferences…

Monitoring the Future (MTF), now in its 35th year, has become one of the nation's most relied-upon sources of information on changes taking place in licit and illicit psychoactive drug use among American adolescents, college students, young adults, and more recently, middle-aged adults. During the last three and a half decades, the study has…

Earthquake, a natural disaster, is among the fundamental problems of many countries. If people know how to protect themselves from earthquake and arrange their life styles in compliance with this, damage they will suffer will reduce to that extent. In particular, a good training regarding earthquake to be received in primary schools is considered…

This study examined the gender issue in the performance of students admitted through Universities Matriculation Examination (UME) and pre-degree into the Nigerian Universities. Ex-post facto design of descriptive research was adopted for the study. A proforma was used to collect data from a sample of two hundred and fifty students from the…

Concerned about reports of a 15% decline in HIV testing among high-risk youth in an earlier study in Pittsburgh, this study was initiated to explore reasons why young people are not getting tested for HIV, while gathering data on their respective level of risk taking behaviors. A total of 580 surveys were collected from youth aged between 14 and…

The study investigated adaptation to a standard electropalatographic (EPG) practise palate in a group of eight adults (mean age = 24 years). The participants read the phrase "a CVC" over four sampling conditions: prior to inserting the palate, immediately following insertion of the palate, 45 minutes after palate insertion, and 3 hours after…

This paper provides a framework for developing sampling designs in mixed methods research. First, we present sampling schemes that have been associated with quantitative and qualitative research. Second, we discuss sample size considerations and provide sample size recommendations for each of the major research designs for quantitative and…

Purpose: The primary aim of the research reported here is to provide strategic guidance for the development of a national communication strategy to improve sun protection practice amongst young people. Design/methodology/approach: The research adopted an exploratory approach, employing qualitative focus groups to represent three population groups,…