The Co-Effects of Query Structure and Expansion on Retrieval Performance in Probabilistic Text Retrieval

The effects of query structures and query expansion (QE) on retrieval performance were tested with a best match retrieval system (InQuery¹). Query structure means the use of operators to express the relations between search keys. Six different structures were tested, representing strong structures (e.g., queries with facets or concepts identified) and weak structures (no concepts identified, a query is a bag of search keys). QE was based on concepts, which were first selected from a searching thesaurus, and then expanded by semantic relationships given in the thesaurus. The expansion levels were (a) no expansion, (b) a synonym expansion, (c) a narrower concept expansion, (d) an associative concept expansion, and (e) a cumulative expansion of all other expansions. With weak structures and Boolean structured queries, QE was not very effective. The best performance was achieved with a combination of a facet structure, where search keys within a facet were treated as instances of one search key (the SYN operator), and the largest expansion.     

Peer‐Mediated Instruction in Inclusive Secondary Social Studies Learning: Direct and Indirect Learning Effects

Ten inclusive middle school social studies classes, including 133 general education students, and 24 students with mild disabilities (21 with learning disabilities and 3 with emotional disabilities), were assigned at random to a traditional instruction condition, or an experimental condition involving classwide peer tutoring with specialized materials and parent training. After 18 weeks of instruction, posttest data revealed that students in the experimental condition gained significantly more than students in the traditional instruction condition. These effects were observed on content included in the tutoring intervention, as well as on related content that was taught but not included in the tutoring intervention. Results are discussed within the context of recent research on inclusive secondary content area instruction.     

Applying Tablet‐Based Performance Support Application for Technicians’ Training at the Israeli Air Force: A Case Study

Performance support systems are mechanisms enabling users) productivity while reducing training expenses as support is being delivered in real time, often eliminating the need for costly pre‐performance training. Mobile technologies have created new opportunities for improved performance support systems, especially for tasks performed outside the offi ce. This article describes the fi rst mobile learning and performance support initiative taken by the Israeli Air Force. The project included the development and eff ectiveness pilot study of a learning and performance support application delivered via tablet to helicopter engine technicians. The application provided support videos and illustrations of maintenance routines, thereby enabling learning and practicing at the same time. Pilot study results show high performance levels of application users compared to those applying traditional methods. Results also show that self‐effi cacy levels were not aff ected by the successful performance achieved when using the mobile performance support application. Plans to expand mobile support use are also described.     

Auflösung der Vorbereitungsfragen zur Facharztprüfung aus Heft 2/2007

Ohne Zusammenfassung     

Wake up Information Literacy Instruction: Ideas for Student Engagement

In this article, three librarians from Santa Fe College, the community college winner of the 2015 ACRL Excellence in Academic Libraries Award, share their successful work in information literacy instruction. While the ACRL award is given for overall achievement, this article focuses upon their creative and varied approaches to instruction, incorporating a wide blend of strategies to reach students across the college. Beginning with targeted approaches to virtual instruction, including broad use of the flipped classroom model, and building in active learning techniques, the librarians at Santa Fe College have built an instruction program that could serve as a model to community college libraries across the country.     

Tracking of physical activity in pubertal boys with different BMI over two-year period

We examined the tracking of physical activity (PA) measured by accelerometers and subjective self- and parental reports in normal weight and overweight and obese pubertal boys over two-year period. In total, 156 boys with mean (±SD) age of 11.53 ± 0.76 at baseline and with mean age of 13.94 ± 0.74 at 2 year follow-up were studied. At baseline and approximately two years later, the boys completed self-report questionnaire and wore an accelerometer for seven consecutive days. On the basis of first year assessment’s body mass index (BMI), the children were grouped as normal weight and overweight and obese groups according to BMI cut-offs. Tracking correlations of objectively measured PA and subjectively measured PA were fairly similar across the 12–14 year-old-boys weight groups over two year period. Tracking correlations of objectively measured PA and subjectively measured PA were not significantly different over two-year period between both BMI groups. The results of the study show that pubertal boys objectively measured PA decreased over two-year period and so the boys started to be less active in their pubertal period.