A replication of the response‐restriction preference assessment

We replicated the response‐restriction (RR) preference assessment and compared results in terms of preference hierarchies to those from free‐operant and multiple stimulus without replacement (MSWO) formats with six children with autism spectrum disorders (ASDs). We also assessed social validity of each format with teachers and clinicians who work with children with ASDs. Complete hierarchies were produced in four of 18 assessments and with MSWO and RR formats only. Results of the social validity assessment varied across raters, with each preference assessment format receiving the highest rating from at least one rater. Results are discussed in terms of practical recommendations and relative to the preference assessment literature as a whole.     

Wrist and arm movements of varying difficulties

Although a great deal of experimental attention has been directed at understanding Fitts' law, only a limited number of experiments have attempted to determine if performance differs across effectors for a given movement difficulty. In three experiments reciprocal wrist and arm movements were compared at IDs of 1.5, 3, 4.5 and 6. When absolute movement requirements and visual display were constant, participants' movement times and response characteristics for the arm and wrist were remarkably similar (Experiment 1). However, when amplitude for wrist movements was reduced to 8° and the gain (4×) for the visual display increased participants' movement time, defined on the basis of kinematic markers (movement onset − movement termination), was increasingly shorter relative to arm movements as movement difficulty was increased (Experiment 2). Experiment 3 where the arm was tested at 32° and 8° with the 8° movements provided the same gain (4×) that was used for the 8° wrist movements in Experiment 2, no advantage was observed for the arm at the shorter amplitude. The results are interpreted in terms of the advantages afforded by the increased gain of the visual display, which permitted the wrist, but not the arm, to more effectively preplan and/or correct ongoing movements to achieve the required accuracy demands. It was also noted that while the wrist was more effective during the actual movement production this was accompanied by an offsetting increase in dwell time which presumably is utilized to dissipate the forces accrued during movement production and plan the subsequent movement segment.     

Effects of interviewer behavior on accuracy of children's responses

Previous research has shown that certain interviewer behaviors can evoke inaccurate answers by children. In the current study, we examined the effects of approving and disapproving statements on the accuracy of 3 children's answers to questions in an interview (Experiment 1). We then evaluated 3 questioning techniques that may be used by interviewers during a forensic interview in which a child provides eyewitness testimony (Experiment 2). All participants responded with more inaccurate answers when approving statements followed inaccurate information and disapproving statements followed accurate information in Experiment 1. During Experiment 2, 1 participant responded most inaccurately when she was requestioned after providing an initial answer, whereas the remaining 2 participants responded most inaccurately when the interviewer provided cowitness information and suggestive questions.     

Modeling the Information Preferences of Parents of Children with Mental Health Problems: A Discrete Choice Conjoint Experiment

Although materials informing parents about children’s mental health (CMH) problems can improve outcomes, we know relatively little about the design factors that might influence their utilization of available resources. We used a discrete choice conjoint experiment to model the information preferences of parents seeking mental health services for 6 to 18 year olds. Parents completed 30 choice tasks presenting experimentally varied combinations of 20 four-level CMH information content, transfer process, and outcome attributes. Latent class analysis revealed three segments with different preferences. Parents in the Action segment (43%) chose materials providing step-by-step solutions to behavioral or emotional problems. They preferred weekly meetings with other parents and coaching calls from a therapist. The Information segment (41%) chose materials helping them understand rather than solve their child’s problems. These parents were more sensitive to logistical factors such as receiving information in groups, the location where information was available, the modality in which the information was presented, and the time required to obtain and use the information. The Overwhelmed segment (16%) reported more oppositional and conduct problems, felt their children’s difficulties exerted a greater adverse impact on family functioning, and reported higher personal depression scores than those in the Action or Information segments. Nonetheless, they did not choose information about, or solutions to, the problems their children presented. Simulations predicted that maximizing utilization and realizing the potential benefits of CMH information would require knowledge transfer strategies consistent with each segment’s preferences.

Drivers’ attitudes toward imperfect distraction mitigation strategies

Studies were conducted to assess driver acceptance of and trust in distraction mitigation strategies. Previous studies have shown that in-vehicle tasks undermine driver safety, and that there is a need for strategies to reduce the effects of in-vehicle distractions. Trust and acceptance of such strategies strongly influence their effectiveness. Different strategies intended to reduce distraction were categorized in a taxonomy. Focus groups were conducted to help refine this taxonomy and explore driver acceptance issues related to these strategies. A driving simulator experiment was then conducted using two of the strategies: an advising strategy that warns drivers of potential dangers and a locking strategy that prevents the driver from continuing a distracting task. These strategies were presented to 16 middle-aged and 12 older drivers in two modes (auditory, visual) with two levels of adaptation (true, false). Older drivers accepted and trusted the strategies more than middle-aged drivers. Regardless of age, all drivers preferred strategies that provided alerts in a visual mode rather than an auditory mode. When the system falsely adapted to the road situation, trust in the strategies declined. The findings show that display modality has a strong effect on driver acceptance and trust, and that older drivers are more trusting and accepting of distraction mitigation technology even when it operates imperfectly.     

How probability theory explains the conjunction fallacy

The conjunction fallacy occurs when people judge a conjunctive statement B‐and‐A to be more probable than a constituent B, in contrast to the law of probability that P(B ∧ A) cannot exceed P(B) or P(A). Researchers see this fallacy as demonstrating that people do not follow probability theory when judging conjunctive probability. This paper shows that the conjunction fallacy can be explained by the standard probability theory equation for conjunction if we assume random variation in the constituent probabilities used in that equation. The mathematical structure of this equation is such that random variation will be most likely to produce the fallacy when one constituent has high probability and the other low, when there is positive conditional support between the constituents, when there are two rather than three constituents, and when people rank probabilities rather than give numerical estimates. The conjunction fallacy has been found to occur most frequently in exactly these situations. Copyright © 2008 John Wiley & Sons, Ltd.     

Suicidal Ideation and Behavior in Adolescents Aged 12–16 Years: A 17‐Year Follow‐Up

The prevalence of suicidal ideation/behavior in 1983 or 1987 and its association with future mental health in 2001 were evaluated in a provincially representative sample of Canadian adolescents (n = 1,248) aged 12 to 16 years. Approximately 13.3% (95% CI = 11.5–15.3) of adolescents self‐reported suicidal ideation/behavior. Adolescent agreement with parent (κ = .07) and teacher (κ = .05) reports at baseline was low because adults identified so few subjects. In adulthood, the associations between adolescent self‐reports of suicidal behavior/ideation and major depression and other mental health indicators were explained by respondent sex and adolescent emotional problems reported in 1983/1987. Adolescents with suicidal behavior/ideation often are not recognized by their parents and teachers and may be at risk for persistent psychiatric problems attributable to coexisting mental health problems early‐on.