The impact of respondent attentiveness on reliability and validity

This study aims to assess whether respondent inattentiveness causes systematic and unsystematic measurement error that influences survey data quality. To determine the impact of (in)attentiveness on the reliability and validity of target measures, we compared respondents from a German online survey (N = 5205) who had passed two attention checks with those who had failed. Our results show that inattentiveness induces both random and systematic measurement error, which impacts estimates of the reliability and validity of multi-item scales. In addition, we conducted a sensitivity analysis, which revealed that the impact of inattentiveness on analyses can be substantial.     

Service learning and the practice of social justice and care

The values of a social justice pedagogy in teacher education are assumed to be firmly established in South African higher education. This article discusses how serviced learning (SL) can provide practical experience of caring and serve the promotion of the ideals of social justice in two initial teacher education programmes. However, an analysis of data in this case study shows that, although SL practice has served as a platform for social justice and for care as two basic educational values, participants were not yet able to verbalize and theorize these values. They were also not able to embed these values in their reflection about service as an inherent component of education. With data from different role players in a number of SL projects, we show that the students’ discourse of what it means to be a caring teacher in a just society has not yet been developed despite the successful practical experience. It was found that, although the students had been building a practice ‘platform’ for service, they had not yet been able to articulate the conceptual intersect of care and social justice clearly. With this epistemological notion in mind, two main themes from the data analysis are discussed: 1) How SL shifted student learning from ideas ‘about’ service to implemented service, and 2) how the practical experience promoted reciprocity in inter-institutional and inter-generational communities of practice.     

Crown width models for woody plant species growing in urban areas of the U.S.

Urban Ecosystems - Crown widths of woody plant species growing in urban areas are of considerable importance as an overall indicator of health and also serve as an important factor for assessing...     

A parameterized perspective on packing paths of length two

We study (vertex-disjoint) packings of paths of length two (i.e., of P ₂’s) in graphs under a parameterized perspective. Starting from a maximal P ₂-packing ℘ of size j we use extremal combinatorial arguments for determining how many vertices of ℘ appear in some P ₂-packing of size (j+1) (if such a packing exists). We prove that one can ‘reuse’ 2.5j vertices. We also show that this bound is asymptotically sharp. Based on a WIN-WIN approach, we build an algorithm which decides, given a graph, if a P ₂-packing of size at least k exists in time O^*(2.448^3k)\mathcal{O}^{*}(2.448^{3k}) .     

A short proof of a result on a Vizing-like problem for integer total domination

In this note, we provide a short proof of a recent result on a Vizing-like problem for integer total domination in graphs given by Li and Hou (J. Comb. Optim., 2008).     

A characterization of graphs with disjoint dominating and paired-dominating sets

A dominating set of a graph is a set of vertices such that every vertex not in the set is adjacent to a vertex in the set, while a paired-dominating set of a graph is a set of vertices such that every vertex is adjacent to a vertex in the set and the subgraph induced by the set contains a perfect matching. In this paper, we provide a constructive characterization of graphs whose vertex set can be partitioned into a dominating set and a paired-dominating set.     

Intercultural Learning in a Multicultural Society

In this contribution the author describes intercultural education as education for higher order skills, that go beyond traditional teaching methods. Intercultural education emphasises interactive skills, it strengthens the self‐esteem of children by giving them a solid foundation to encounter the unknown.     

Constraint bipartite vertex cover: simpler exact algorithms and implementations

Constraint bipartite vertex cover is a graph-theoretical formalization of the spare allocation problem for reconfigurable arrays. We report on an implementation of a parameterized algorithm for this problem. This has led to considerable simplifications of the published, quite sophisticated algorithm. Moreover, we can prove that the mentioned algorithm could be quite efficient in practial situations. We also discuss possible generalizations and enhancements.