In sequential mastery testing (SMT), assessment via computer is used to classify examinees into one of two mutually exclusive categories. Unlike paper-and-pencil tests, SMT has the capability to use variable-length stopping rules. One approach to shortening variable-length tests is stochastic curtailment, which halts examination if the probability…

We compared the prevalence and correlates of adolescent suicidal ideation and attempts in two nationally representative probability samples of adolescents interviewed in 1995 (National Survey of Adolescents; N = 4,023) and 2005 (National Survey of Adolescents-Replication; N = 3,614). Participants in both samples completed a telephone survey that…

The purpose of this study is to apply the attribute hierarchy method in an operational diagnostic mathematics program at Grades 3 and 6 to promote cognitive inferences about students' problem-solving skills. The attribute hierarchy method is a psychometric procedure for classifying examinees' test item responses into a set of structured attribute…

The garlic problem presented in this article develops several themes related to dimensional analysis and also introduces students to a few basic statistical ideas. This garlic problem was used in a university preparatory chemistry class, designed for students with no chemistry background. However, this course is unique because one of the primary…

Every person in his lifetime has many times experienced the miraculous impact of the fairy-tale on his imagination, mind and feelings. But we seldom reflect upon the content not only in the ethical aspect of fairy-tales but also as a source of different kinds of knowledge, among them the knowledge of mathematics. The use of fairy-tales in lessons…

Tourette syndrome (TS) is an inheritable, childhood-onset neurologic disorder marked by persistent multiple motor tics and at least one vocal tic. Tics are involuntary, repetitive, stereotypic movements or vocalizations that are usually sudden and rapid and often can be suppressed for short periods. The prevalence of TS is uncertain; the broad…

This study investigates whether children's production and recognition of obligatory liaison sequences in French depend on the singular/plural orientation of nouns. Certain nouns occur more frequently in the plural (e.g., "arbre" "tree"), whereas others are found more often in the singular (e.g., "arc-en-ciel" "rainbow"). In the input, children…

This paper describes and evaluates the use of measurement decision theory (MDT) to classify examinees based on their item response patterns. The model has a simple framework that starts with the conditional probabilities of examinees in each category or mastery state responding correctly to each item. The presented evaluation investigates: (1) the…

The classroom activity described here allows mathematically mature students to explore the role of mean, median and mode in a decision-making environment. While students discover the importance of choosing a measure of central tendency, their understanding of probability distributions, maximization, and prediction is reinforced through active…

In this study we assessed the behavioral presentation of social anxiety in Cornelia de Lange syndrome (CdLS) using a contrast group of Cri du Chat syndrome (CdCS). Behaviors indicative of social anxiety were recorded in twelve children with CdLS (mean age = 11.00; SD = 5.15) and twelve children with CdCS (8.20; SD = 2.86) during social…

The game of Matching Pennies (MP), a simplified version of the more popular Rock, Papers, Scissors, schematically represents competitions between organisms with incentives to predict each other's behavior. Optimal performance in iterated MP competitions involves the production of random choice patterns and the detection of nonrandomness in the…

In 5 experiments, we studied precautionary decisions in which participants decided whether or not to buy insurance with specified cost against an undesirable event with specified probability and cost. We compared the risks taken for precautionary decisions with those taken for equivalent monetary gambles. Fitting these data to Tversky and…

Background: Sleep problems are common in individuals with intellectual disability. Little is known about sleep in children and adults with Cri du Chat syndrome (CDC). Method: Sleep was investigated in 30 individuals with CDC using a sleep questionnaire. Sleep problems and sleep behaviours in individuals with CDC were compared with individuals with…

Brain imaging studies of adults with psychopathy have identified structural and functional abnormalities in limbic and prefrontal regions that are involved in emotion recognition, decision-making, morality and empathy. Among children with conduct problems, a small subgroup presents callous-unemotional traits thought to be antecedents of…

Descriptive observations were conducted to record problem behavior displayed by participants and to record antecedents and consequences delivered by caregivers. Next, functional analyses were conducted to identify reinforcers for problem behavior. Then, using data from the descriptive observations, lag-sequential analyses were conducted to examine…