The misconception of the regression-based discrepancy operationalization in the definition and research of learning disabilities

In this article, I argue that the regression-based discrepancy method used in the diagnosis of learning disabilities is invalid because it is inconsistent with the underlying underachievement concept of which it is intended to be the operationalization. I mathematically demonstrate that the regression-based discrepancy method largely reflects achievement-specific determinants, thereby defeating its own object of describing aptitude-achievement discrepancies. The implications for research examining the role of intelligence in learning disabilities are outlined.     

Detecting Differential Speededness in Multistage Testing

A potential undesirable effect of multistage testing is differential speededness, which happens if some of the test takers run out of time because they receive subtests with items that are more time intensive than others. This article shows how a probabilistic response-time model can be used for estimating differences in time intensities and speed between subtests and test takers and detecting differential speededness. An empirical data set for a multistage test in the computerized CPA Exam was used to demonstrate the procedures. Although the more difficult subtests appeared to have items that were more time intensive than the easier subtests, an analysis of the residual response times did not reveal any significant differential speededness because the time limit appeared to be appropriate. In a separate analysis, within each of the subtests, we found minor but consistent patterns of residual times that are believed to be due to a warm-up effect, that is, use of more time on the initial items than they actually need.     

Regional inequality in reading performance: an exploration in Belgium

In the 2009 Programme for International Student Assessment, the Flemish community of Belgium outscored its French community in reading, with low achievers accounting for a large proportion of the score gaps. In this study, between-community comparisons based on the Blinder-Oaxaca decomposition method showed that the Flemish community benefits largely from its policies and practices of giving schools relative autonomy in resource allocation, promoting good student conduct, and decreasing grade retention. Between-community comparisons using the Juhn-Murphy-Pierce decomposition method showed that compared to their Flemish peers in the same percentile, low achievers in the French community are hindered more by their relatively low grade level; disadvantageous school economic, social, and cultural composition; and negative school supportive climate while medium and high achievers benefit more from their advantageous school economic, social, and cultural composition; positive supportive climate; and high proportion of qualified teachers in schools.     

Clear Self,Better Relationships: Adolescents’ Self‐Concept Clarity and Relationship Quality With Parents and Peers Across 5 Years

This study examined reciprocal associations between adolescents’ self‐concept clarity (SCC) and their relationship quality with parents and best friends in a five‐wave longitudinal study from age 13 to 18 years. In all, 497 adolescents (57% boys) reported on their SCC and all informants (i.e., adolescents, both parents, and adolescents’ best friends) reported on support and negative interaction. Within‐person cross‐lagged analyses provided systematic evidence for both parent effects and child effects, with the direction of effects being strongly dependent on the relational context. For example, higher maternal support predicted higher adolescent SCC, supporting a parent effects perspective, whereas higher SCC predicted lower paternal negative interaction, supporting a child effects perspective. Peer effects on adolescent SCC were not consistently found across adolescent and best friend reports.     

The relationship between student-generated learning issues and self-study in problem-based learning

A major assumption of problem-based learning (PBL) is that learning issues, generated by students while discussing a problem, are used as guides for self-directed learning activities. This assumption, though basic to PBL, has never been tested. At the University of Limburg, the Netherlands, two procedures have been developed that reflect the extent to which students are able to identify important learning issues given a particular problem, and whether subsequent, independent, learning corresponds with these learning issues. The focus of the present article will be on the relationship between the two. We have explored to what extent student-generated learning issues are a major factor influencing the nature of students' self-study, or whether other factors may be involved in decisions on what to study and how much time to spend on topics selected. First, the production of learning issues was studied and represented as the percentage of overlap between learning issues raised by students and pre-set faculty objectives for each problem. The second procedure consisted of the administration of a Topic Checklist (TOC) which purports to measure students' actual self-directed learning activities. The TOC consists of a list of topics specifying the intended course content. Students were asked to indicate on a five-point Likert scale how much time they had spent studying each topic and to what degree they had mastered that topic. Third, learning issues and TOC topics were compared directly in a qualitative sense. Comparisons between the procedures revealed that a low proportion of variance of TOC scores could be predicted from the percentage of faculty objectives identified for each problem and the direct match between learning issues and TOC scores. It is concluded that scrutinizing student-generated learning issues and topics covered during self-study may provide information about what content is covered by students in tutorial groups. The discrepancy between the results of the measurements suggests, however, that learning issues produced during group discussion are not the sole source on which students base self-study decisions. Several other factors may be involved, such as tutor guidance, content already covered in previous units, issues raised during sessions with resource persons, and the nature of the learning resources available. Therefore, the relationship between learning issues and content covered during self-study is not as straightforward as is suggested.     

Optimal cognitive distance and absorptive capacity

In this paper we test the relation between cognitive distance and innovation performance of firms engaged in technology-based alliances. The key finding is that the hypothesis of an inverted U-shaped effect of cognitive distance on innovation performance of firms is confirmed. Moreover, as expected, we found that the positive effect for firms is much higher when engaging in more radical, exploratory alliances than in more exploitative alliances. The effect of cumulative R&D turns out to be mixed. It appears to increase absorptive capacity, as expected, but there is clear evidence that it also reduces the effect of cognitive distance on novelty value, making it increasingly difficult to find additional novelty.     

Automated Test‐Form Generation

In automated test assembly (ATA), the methodology of mixed‐integer programming is used to select test items from an item bank to meet the specifications for a desired test form and optimize its measurement accuracy. The same methodology can be used to automate the formatting of the set of selected items into the actual test form. Three different cases are discussed: (i) computerized test forms in which the items are presented on a screen one at a time and only their optimal order has to be determined; (ii) paper forms in which the items need to be ordered and paginated and the typical goal is to minimize paper use; and (iii) published test forms with the same requirements but a more sophisticated layout (e.g., double‐column print). For each case, a menu of possible test‐form specifications is identified, and it is shown how they can be modeled as linear constraints using 0–1 decision variables. The methodology is demonstrated using two empirical examples.     

Students’ Overuse of Linearity: An Exploration in Physics

In mathematics education, a vast amount of research has shown that students of different ages have a strong tendency to apply linear or proportional models anywhere, even in situations where they are not applicable. For example, in geometry it is known that many students believe that if the sides of a figure are doubled, the area is doubled too. However, also history of science provides several cases of thinkers who inadequately postulated linear relations to describe situations. This article focuses on secondary school students’ over-reliance on linearity in physics. Now and then, science educators report students’ tendency to assume and impose linear relations in physics, but—as far as we know—no substantial efforts were undertaken to study this phenomenon systematically. We conducted an empirical investigation aimed at identifying the competence of 8th- and 11th-graders—before and after being taught the relevant physical topics—to qualitatively grasp various situations in physics, as well as their tendency to quantify that qualitative insight linearly. The results provide an ambivalent picture of students’ overuse of linearity in physics: Although linear reasoning is sometimes used as a default strategy, even after instruction that addresses the relevant physical contents, this study also indicates that context is taken into account more often than is suggested by research on mathematical problem solving.     

Test Design and Speededness

A critical component of test speededness is the distribution of the test taker’s total time on the test. A simple set of constraints on the item parameters in the lognormal model for response times is derived that can be used to control the distribution when assembling a new test form. As the constraints are linear in the item parameters, they can easily be included in a mixed integer programming model for test assembly. The use of the constraints is demonstrated for the problems of assembling a new test form to be equally speeded as a reference form, test assembly in which the impact of a change in the content specifications on speededness is to be neutralized, and the assembly of test forms with a revised level of speededness.