Balancing fit and parsimony to improve Q-matrix validation

The Q-matrix identifies the subset of attributes measured by each item in the cognitive diagnosis modelling framework. Usually constructed by domain experts, the Q-matrix might contain some misspecifications, disrupting classification accuracy. Empirical Q-matrix validation methods such as the general discrimination index (GDI) and Wald have shown promising results in addressing this problem. However, a cut-off point is used in both methods, which might be suboptimal. To address this limitation, the Hull method is proposed and evaluated in the present study. This method aims to find the optimal balance between fit and parsimony, and it is flexible enough to be used either with a measure of item discrimination (the proportion of variance accounted for, PVAF) or a coefficient of determination (pseudo-R²). Results from a simulation study showed that the Hull method consistently showed the best performance and shortest computation time, especially when used with the PVAF. The Wald method also performed very well overall, while the GDI method obtained poor results when the number of attributes was high. The absence of a cut-off point provides greater flexibility to the Hull method, and it places it as a comprehensive solution to the Q-matrix specification problem in applied settings. This proposal is illustrated using real data.     

Evaluation of “staying on track”: An early identification,tracking, and referral system

The “Staying on Track” project tracked infants, preschoolers, and their families in Brockville, Ontario, Canada for a period of 3 years. Public health nurses at preassigned intervals provided information and counseling for families and made referrals to other agencies if problems were judged to be beyond the expertise of the “Staying on Track” staff. To assess the effectiveness of the program in improving child development, a cohort design was selected to allow development to be assessed over 5½ years in 3 years. Three cohorts and a comparison group were included in the study. Each cohort received different procedures for identification and tracking. Cohort 1 received at least four home visits, cohort 2 received three clinic visits, and cohort 3 received one clinic visit. Intervention and follow-up from these visits included home visits, phone calls, and referrals for all three cohorts. Comparing cohort 1 to cohort 2 at 18 months, highly significant effects were found; few significant differences were found at 3½ years between cohort 2 and 3 and very few positive effects were found for 5½-year-old children who had been in the tracking system since they were 3½ years of age. The results are discussed and recommendations are made about the implications of the study for service provision. © 1998 Michigan Association for Infant Mental Health     

The concave cusp as a determiner of figure-ground

The tendency to interpret as figure, relative to background, those regions that are lighter, smaller, and, especially, more convex is well known. Wherever convex opaque objects abut or partially occlude one another in an image, the points of contact between the silhouettes form concave cusps, each indicating the local assignment of figure versus ground across the contour segments. It is proposed that this local geometric feature is a preattentive determiner of figure-ground perception and that it contributes to the previously observed tendency for convexity preference. Evidence is presented that figure-ground assignment can be determined solely on the basis of the concave cusp feature, and that the salience of the cusp derives from local geometry and not from adjacent contour convexity.     

The Cross‐cultural Transportability of Situational Judgment Tests: How does a US‐based integrity situational judgment test fare in Spain?

Despite the globalization of HRM, there is a dearth of research on the potential use of contextualized selection instruments such as situational judgment tests (SJTs) in other countries than those where the selection instruments were originally developed. Therefore, two studies are conducted to examine the transportability of an integrity SJT that was originally developed in the United States to a Spanish context. Study 1 showed that most SJT scenarios (16 out of 19) that were developed in the United States were also considered realistic in a Spanish context. In Study 2, the item option endorsement patterns converged to the original scoring scheme, with the exception of two items. In addition, there were high correlations between the original US empirical scoring scheme and two empirical scoring schemes that were tailored to the Spanish context (i.e., mode consensus scoring and proportional consensus scoring). Finally, correlations between the SJT integrity scores and ratings on a self‐report integrity measure did not differ significantly from each other according to the type of scoring key (original US scoring vs. Spanish scoring keys). Overall, these results shed light on potential issues and solutions related to the cross‐cultural use of contextualized selection instruments such as SJTs.