Indexing consistency in MEDLINE

The quality of indexing of periodicals in a bibliographic data base cannot be measured directly, as there is no one "correct" way to index an item. However, consistency can be used to measure the reliability of indexing. To measure consistency in MEDLINE, 760 twice-indexed articles from 42 periodical issues were identified in the data base, and their indexing compared. Consistency, expressed as a percentage, was measured using Hooper's equation. Overall, checktags had the highest consistency. Medical Subject Headings (MeSH) and subheadings were applied more consistently to central concepts than to peripheral points. When subheadings were added to a main heading, consistency was lowered. "Floating" subheadings were more consistent than were attached subheadings. Indexing consistency was not affected by journal indexing priority, language, or length of the article. Terms from MeSH Tree Structure categories A, B, and D appeared more often than expected in the high-consistency articles; whereas terms from categories E, F, H, and N appeared more often than expected in the low-consistency articles. MEDLINE, with its excellent controlled vocabulary, exemplary quality control, and highly trained indexers, probably represents the state of the art in manually indexed data bases.     

Writing Characteristics of Students with Attention Deficit Hyperactive Disorder: A Meta‐Analysis

Students with Attention Deficit Hyperactivity Disorders (ADHD) frequently experience significant difficulty mastering basic academic skills. This meta‐analysis focuses on one specific potential area of learning difficulties for these students: namely, writing. To identify the extent and depth of the potential writing challenges faced by students with ADHD, we conducted a meta‐analysis comparing the writing performance of grade 1 to 12 students with ADHD to their normally achieving peers. We located 44 papers, yielding 45 studies with 87 effect sizes. The average weighted effect sizes showed that students with ADHD obtained lower scores than their normally achieving peers for writing quality (–0.78), output (–0.64), number of genre elements (–0.69), vocabulary (–0.76), spelling (–0.80), and handwriting (–0.62). Contrary to expectations, moderator analyses found that neither study quality nor the source from which ADHD students were drawn (i.e., school/community vs. clinic/hospital) accounted for variability above sampling error alone.     

“They Even Speak Tsotsitaal with Their Teachers at School”: The Use (and Abuse) of African Urban Youth Languages in Educational Contexts

Abstract

African Urban Youth Languages (AUYLs) are increasingly coming under the spotlight of linguists and sociolinguists across the continent, who are investigating their relationship to standard and/or vernacular varieties. Simultaneously, they are being discussed by educators and education researchers, although little has yet been published in this critical area. The difficulties for educators posed by students speaking “non-standard” varieties has been highlighted by recent studies investigating literacy and language in the classroom. This article presents an overview of some of the challenges posed to education by AUYLs. It considers recent studies of AUYLs in educational contexts from around the continent. It then presents data from South Africa which highlights different orientations towards the South African AUYL “Tsotsitaal” in educational domains. The argument is made that the position of both teachers and pupils is vulnerable, and that the legitimacy of the distinction between standard language and urban vernacular language needs to be reconsidered.     

Effects of varying trial distribution,intra- and extramaze cues,and amount of reward on proactive interference in the radial maze

Rats are typically less accurate in their arm selections in the radial maze over successive trials in a session (Roberts & Dale, 1981). In the present study, rats’ choice accuracy declined when such trials were separated by 2-min (massed) but not by 2-h (spaced) intertriai intervals. Changing intramaze visual/tactile arm stimuli (Experiments 1 and 3) or extramaze landmark stimuli (Experiment 4) between trials weakened the massed-trials effect, but changing the number of food pellets per arm, either alone or in conjunction with changes in intramaze cues (Experiments 2 and 3), did not. The rats also tended to avoid the spatial locations of their last four choices on a previous trial during their first four choices on a current trial, and more so with massed than with spaced trials. These findings indicate that intertriai proactive interference (PI) occurred only with massed trials and was weakened by changing intra- and extramaze cues between such trials.