Efficient probabilistic XML query processing using an extended labeling scheme and a lightweight index

Recently there is a growing interest in the data model and query processing for probabilistic XML data. There are many potential applications of probabilistic data, and the XML data model is suitable to represent hierarchical information and data uncertainty of different levels naturally. However, the previously proposed probabilistic XML data models and query processing techniques separate finding data matches with evaluating the probabilities of results. Therefore, they should repeatedly access the data and need to get full data of paths given in queries to calculate the probabilities of results.     

An administrative mess: A case study from the officiating community

This case is written for instructors of classes focused on strategic management, organisational behaviour, human resource management, and/or an officiating course. The case highlights the numerous administrative processes a new employee in a sport organisation would face. Although the case is fictional it is based on the authors’ personal and professional experiences in athletics administration and officiating, and further draws upon the authors’ research in the area of officiating. Consequently, this case study was constructed based on first-hand observation, interviews and conversation with numerous officials and administrators, and through the examination of documents frequently used to manage officials. As a result, the case provides an opportunity for students to critically evaluate and address: (1) a sport organisation's policies and procedures; (2) issues related to human resource management within a sport setting; (3) the managerial response after an organisational failure.     

Conceptions of quality in four different disciplines

Abstract

The paper is based on a book (written by the author and his colleague Markku Lehikoinen) dealing with definitions of quality and views on the applicability of different methods of quality assessment to four different disciplinary fields: physics, biology, sociology and history. The paper focuses on conceptions and definitions of quality voiced by scholars representing the different disciplines. The study involved semi‐structured in depth interviews with 33 experienced scholars. The disciplines under study were chosen to represent diverse disciplinary cultures, with the aim of finding out about the potential impact of (social and cognitive) cultural characteristics of the disciplines on conceptions of quality. The findings show both common views across disciplinary fields and disciplinary differences.     

Graphical Analysis of Test Items

Graphical Item Analysis (GIA) visually displays the relationship between the total score on a test and the response proportions of the correct and false alternatives of a multiple-choice item. The GIA method provides essential and easily interpretable information about item characteristics (difficulty, discrimination and guessing rate). Low quality items are easily detected with the GIA method because they show response proportions on the correct alternative which decrease with an increase of the total score, or display response proportions of one or more false alternatives which do not decrease with an increase of the total score. The GIA method has two main applications. Firstly, it can be used by researchers in the process of identifying items that need to be excluded from further analysis. Secondly, it can be used by test constructors in the process of improving the quality of the item bank. GIA enables a better understanding of test theory and test construction, especially for those without a background in psychometrics. In this sense, the GIA method might contribute to reducing the gap between the world of psychometrists and the practical world of constructors of achievement tests.     

The effects of mid-flight whole-body and trunk rotation on landing mechanics: implications for anterior cruciate ligament injuries

ABSTRACT

The purpose was to quantify the effects of mid-flight whole-body and trunk rotation on knee mechanics in a double-leg landing. Eighteen male and 20 female participants completed a jump-landing-jump task in five conditions: no rotation, testing leg ipsilateral or contralateral (WBRC) to the whole-body rotation direction, and testing leg ipsilateral (TRI) or contralateral to the trunk rotation direction. The WBRC and TRI conditions demonstrated decreased knee flexion and increased knee abduction angles at initial contact (2.6 > Cohen’s dz > 0.3) and increased peak vertical ground reaction forces and knee adduction moments during the 100 ms after landing (1.7 > Cohen’s dz > 0.3). The TRI condition also showed the greatest knee internal rotation angles at initial contact and peak knee abduction and internal rotation angles and peak knee extension moments during the 100 ms after landing (2.0 > Cohen’s dz > 0.5). Whole-body rotation increased contralateral knee loading because of its primary role in decelerating medial-lateral velocities. Trunk rotation resulted in the greatest knee loading for the ipsilateral knee due to weight shifting and mechanical coupling between the trunk and lower extremities. These findings may help understand altered trunk motion in anterior cruciate ligament injuries.     

Where is the “theory” within the field of educational technology research?

Critics often characterise the study of educational technology as under-theorised. To test this assertion and to determine the extent of this criticism, the present paper reports an in-depth analysis of the 503 most recent empirical articles published in three selected education-technology-related journals (Computers & Education; Learning, Media and Technology; and British Journal of Educational Technology). These journals were selected because they publish studies related to all education settings rather than focusing on only a certain segment such as higher education; they have broad geographical catchment; and they were the most highly ranked journals in terms of their 2017 journal citation impact factor. The present paper examines how explicitly existing theory was identified in previous research, how theories were applied and how often these theories were advanced in education technology research. In the majority of cases, explicit engagement with theory was absent. Many studies either were wholly bereft of theories or made vague use of theory. Where theory was explicit, the articles were more likely to use theory to conceptualise the research, to inform the data collection or analysis process and to discuss the results. Very few articles reported findings that help us to learn something new about a particular theory (ie, little evidence of theory advancement).