Distributed delay input shaper design by optimizing smooth kernel functions

The aim of this paper is the development of a general class of input shapers with distributed time delay which leads to retarded spectral properties. The design of the shaper is formulated as a multi-objective optimization problem, where response time and robustness, expressed in terms of residual vibrations, are the main objectives. As a part of the optimization formulation, common requirements for input shapers such as non-decreasing step response and unity steady state gain are considered in the design. Moreover, additional optional requirements, such as smoothness of a step response, jerk and even jounce limits can be added to optimization procedure. The resulting problem can be solved using convex optimization techniques. Several illustrative examples are presented in comparison with classical input shaping techniques. Finally, implementation aspects are discussed. The paper is accompanied by an implementation in MATLAB, including a user-friendly interface for the interactive shaper design.     

A Case Study in the Measurement of Educational Efficiency in Open and Distance Learning

Open and distance learning (ODL) gives learners control of the time, place, and pace of learning, often being characterized as flexible learning. However, this flexibility goes hand‐in‐hand with procrastination and non‐completion. As a result, the efficiency of the educational process is of importance to ODL providers, government funding agencies, and learners themselves. Despite its importance, measuring efficiency in ODL is problematic. This article presents a case study in measuring educational efficiency using a method which reflects the special characteristics of ODL. The article concludes with a discussion of the wider applicability of the measurement method in the context of lifelong learning.     

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.     

Local Observed‐Score Kernel Equating

Three local observed‐score kernel equating methods that integrate methods from the local equating and kernel equating frameworks are proposed. The new methods were compared with their earlier counterparts with respect to such measures as bias—as defined by Lord's criterion of equity—and percent relative error. The local kernel item response theory observed‐score equating method, which can be used for any of the common equating designs, had a small amount of bias, a low percent relative error, and a relatively low kernel standard error of equating, even when the accuracy of the test was reduced. The local kernel equating methods for the nonequivalent groups with anchor test generally had low bias and were quite stable against changes in the accuracy or length of the anchor test. Although all proposed methods showed small percent relative errors, the local kernel equating methods for the nonequivalent groups with anchor test design had somewhat larger standard error of equating than their kernel method counterparts.     

Testing elementary and secondary school students’ ability to perform historical perspective taking: the constructing of valid and reliable measure instruments

Historical reasoning competencies play an important role in history education. However, valid and reliable large-scale measurement instruments to assess these competencies are scarce. This study considers two instruments for measuring students’ ability to perform historical perspective taking (HPT) as a historical reasoning competency. The instruments have been tested for validity and reliability among 1,270 Dutch upper elementary and secondary school students, ranging in age from 10 to 17 years. One instrument offers effective validity and reliability and can map HPT performance among a large and heterogeneous student population. The results show that even upper elementary school students are capable of performing HPT. However, as students age, their ability to perform HPT increases. Differences regarding the ability to perform HPT were also found between educational levels. Pre-university students performed HPT more successfully compared to students at lower educational levels. The results of this study can be used to gain insight into the construct of HPT and into how historical reasoning competencies such as HPT can be measured. Furthermore, the results provide insight into how differences between students, such as age and educational levels, influence the performance of HPT.     

An Embedded and Embodied Cognition Review of Instructional Manipulatives

Recent literature on learning with instructional manipulatives seems to call for a moderate view on the effects of perceptual and interactive richness of instructional manipulatives on learning. This “moderate view” holds that manipulatives’ perceptual and interactive richness may compromise learning in two ways: (1) by imposing a very high cognitive load on the learner, and (2) by hindering drawing of symbolic inferences that are supposed to play a key role in transfer (i.e., application of knowledge to new situations in the absence of instructional manipulatives). This paper presents a contrasting view. Drawing on recent insights from Embedded Embodied perspectives on cognition, it is argued that (1) perceptual and interactive richness may provide opportunities for alleviating cognitive load (Embedded Cognition), and (2) transfer of learning is not reliant on decontextualized knowledge but may draw on previous sensorimotor experiences of the kind afforded by perceptual and interactive richness of manipulatives (Embodied Cognition). By negotiating the Embedded Embodied Cognition view with the moderate view, implications for research are derived.     

The prevalence of poor reading in Dutch special elementary education

The relative frequency of poor readers in Dutch general elementary education (GEE) and special elementary education (SEE) and the characteristics of their reading performance were investigated using a lexical decision procedure. According to the same norms that identified 9% of students as poor readers in GEE, no less than 73% of the students in SEE were classified as poor readers. On average, the GEE poor readers were better readers than those in SEE, but the findings do not point to substantial differences in reading processes between the two reader groups. Hypotheses about the nature of the referral process that may cause this surprisingly strong relation between poor reading ability and SEE placement are advanced.