To determine familial risk of early suicide, data on cause of death of all Dutch residents aged 20-55 years who died between 1995 and 2001 were linked to data of their parents. Men whose father died by suicide had a higher odds of suicide themselves, relative to men whose father died of other causes (Odds Ratio (OR): 2.5; 95% confidence interval:…

Recently, researchers have investigated differences in decision making based on description and experience. We address the issue of when experience-based judgments of probability are more accurate than are those based on description. If description is well understood ("transparent") and experience is misleading ("wicked"), it…

A robust finding in social psychology is that people judge negative events as less likely to happen to themselves than to the average person, a behavior interpreted as showing that people are "unrealistically optimistic" in their judgments of risk concerning future life events. However, we demonstrate how unbiased responses can result in data…

This investigation examined the ability of 44 preschool children to acquire novel words embedded in storybook contexts. Previous investigations of word learning have typically consisted of novel words for which synonyms exist. It is argued that the acquisition of unfamiliar words that refer to existing concepts that already have labels is not…

The 1973 Raising of the School Leaving Age from 15 to 16 has been used to identify returns to years' schooling. However, because the first set of "high stakes" exams are taken in the UK at age 16, the reform affected the proportion with qualifications, as well as schooling length. In order to shed light on whether the returns reflect the…

Effectively teaching the concepts of osmosis to college-level students is a major obstacle in biological education. Therefore, a novel computer model is presented that allows students to observe the random nature of particle motion simultaneously with the seemingly directed net flow of water across a semipermeable membrane during osmotic…

Experimental data are analysed statistically to allow researchers to draw conclusions from a limited set of measurements. The hard fact is that researchers can never be certain that measurements from a sample will exactly reflect the properties of the entire group of possible candidates available to be studied (although using a sample is often the…

Malay (Rumi) is alphabetic and has a transparent, agglutinative system of affixation. We manipulated language-specific junctural phonetics in Malay and English to investigate whether morphophonemic L1-knowledge influences L2-processing. A morpheme decision task, "Does this "nonword" sound like a mono- or bi-morphemic English word?", was developed…

Complex survey data are collected by means other than simple random samples. This creates two analytical issues: nonindependence and unequal selection probability. Failing to address these issues results in underestimated standard errors and biased parameter estimates. Using data from the nationally representative Head Start Family and Child…

This study investigated the accuracy of several early literacy measures that have been used in research and practice for first grade reading screening. A set of measures, Word Identification Fluency (WIF), Letter Naming Fluency, Phoneme Segmentation Fluency, and Nonsense Word Fluency, were administered as screening measures with 138 first grade…

This study elaborates the Rasch differential item functioning (DIF) model formulation under the marginal maximum likelihood estimation context. Also, the Rasch DIF model performance was examined and compared with the Mantel-Haenszel (MH) procedure in small sample and short test length conditions through simulations. The theoretically known…

We study the relationship between parental job loss and children's academic achievement using data on job loss and grade retention from the 1996, 2001, and 2004 panels of the Survey of Income and Program Participation. We find that a parental job loss increases the probability of children's grade retention by 0.8 percentage points, or around 15%.…

Developmental education has been cited as one of the most difficult issues facing community colleges. Despite the controversy and changes to educational policy regarding developmental education, there is a notable dearth of rigorous research measuring the causal effect of remediation on community college student outcomes. The present study uses…

To ensure the competitiveness of the USA in the global economy, and its role as a leader in science and engineering, it is important to cultivate the next generation of home grown mathematicians. However, while universities across the USA offer calculus classes to thousands of undergraduate students each year, very few of them go on to major in…

Using data from waves 1 through 5 of the National Longitudinal Transition Study-2, this study used propensity score techniques to assess the relationships between general education inclusion and college enrollment rates among youth with Autism Spectrum Disorder (ASD). Data show that 2- or 4-year college enrollment rates were significantly higher…