The Role of Random Allocation in Randomized Controlled Trials: Distinguishing Selection Bias from Baseline Imbalance

Background: This paper addresses one threat to the internal validity of a randomized controlled trial (RCT), selection bias. Many authors argue that random allocation is used to ensure baseline equality between study conditions in a given study and that statistically significant differences at pretest mean that randomisation has failed.   Purpose: The purpose of this study was to clarify the role of random allocation in an RCT study. Is the role of random allocation to protect against selection bias? And does it have a further role, namely to ensure baseline equality and the absence of statistically significant differences between study conditions at pretest?   Setting: The participants for this study were 229 children in 1st and 2nd grade and data were collected as part of an RCT evaluation of a volunteer reading programme piloted in Ireland, Wizards of Words (WoW).   Intervention: Not applicable.   Research design: The allocation procedure adopted in this study was stratified and blocked random allocation.   Data collection and analysis: Data were collected using standardised and criterion-referenced tests of reading ability. Data were collected by qualified Speech and Language Therapists. Independent-samples t-tests were used to analyse pretest data.   Findings: The role of random allocation is to protect against selection bias, and statistically significant baseline differences can result even when random allocation has been successful. Whether or not random allocation has been successful is determined by the generation of the random allocation sequence and the steps taken to ensure its concealment. The size of differences between study conditions at pretest can be important for the analysis of posttest data but does not by itself determine whether random allocation was successful. In addition, there are serious concerns about the appropriateness of tests of significance when comparing two study conditions at pretest. Keywords: baseline equality; baseline imbalance; random allocation; selection bias; test of statistical significanc

Evaluation of the Restorative Practices Programme of the Childhood Development Initiative

This report presents the key findings of an independent evaluation, undertaken by the UNESCO Child and Family Research Centre at the National University of Ireland, Galway, of the Restorative Practice Programme, part of the Childhood Development Initiative's (CDI) Community Safety Initiative (CSI). The study comprises (i) a process study evaluation of programme implementation under the headings of programme utilisation, programme organisation and programme fidelity; and (ii) an outcomes study evaluation of programme impact on participants' work, lives, organisations and family, and also the wider impact on community building and collaborative action

Classroom Test Construction: The Power of a Table of Specifications

Classroom tests provide teachers with essential information used to make decisions about instruction and student grades. A table of specification (TOS) can be used to help teachers frame the decision making process of test construction and improve the validity of teacher\u27s evaluations based on tests constructed for classroom use. In this article we explain the purpose of a TOS and how to use it to help construct classroom tests. Accessed 155,500 times on https://pareonline.net from February 21, 2013 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Stability of Shannon Embankments

During the operating life of the Shannon Embankments, stability and seepage problems have occurred which caused concern regarding long term safety. The geology was studied, a comprehensive scheme of field and laboratory investigation was undertaken and the stability was analyzed and back calculated under failure conditions. The relative significance of various parameters was studied and provided the basis for the design of remedial measures. This paper deals in detail with the study of the stability of one embankment section (Fort Henry) and the recommendations on remedial measures

Exploring the Relationships of Teachers' Efficacy, Knowledge, and Pedagogical Beliefs: A Multimethod Study

Teacher efficacy has been related to many positive educational outcomes (e.g., Tschannen-Moran, Woolfolk-Hoy, & Hoy, 1998). However, a literature review revealed little research assessing the relation of teacher efficacy to pedagogical knowledge or pedagogical beliefs. This work explored the relations among these constructs. A proposed model was tested in which efficacy served as a mediator between teachers' demonstrated knowledge, pedagogical beliefs, and performance. One hundred-twenty preservice and 102 experienced teachers completed a test packet that assessed demographic information, knowledge, efficacy, beliefs, and teachers' ability to assess common instructional situations. Three experienced high-knowledge teachers with differing efficacy levels participated in in-depth interviews for instrumental case study analysis. Correlational analyses demonstrated a significant relation for pedagogical beliefs and efficacy. The data for preservice and experienced teachers was fit to the proposed model and analyzed by path analysis. The resulting models differed for each group. Preservice teachers' knowledge related directly to performance, and did not relate to efficacy. Beliefs related to performance as well as efficacy. Experienced teachers' knowledge and beliefs related to teacher efficacy. However, efficacy was not related to performance. The relation between demonstrated knowledge and teacher efficacy was negative in nature, indicating that teachers with greater demonstrated knowledge tended to have a lower sense of efficacy. Case study analysis revealed a tendency in these teachers to verbalize efficacy beliefs as explanations for not engaging in particular teaching practices. Teacher beliefs also emerged as a common theme in the case studies, specifically beliefs about the nature and evaluation of teaching. This investigation confirmed the need to further explore the relations of teachers' knowledge, pedagogical beliefs, and efficacy. Of particular interest are the beliefs teachers hold about the value of pedagogical knowledge, the nature of teaching, and the knowledge content (e.g., subject matter) that is most essential for successful teaching. Future studies should explore in greater depth the interrelations of these constructs

Developing a Measure of Scientific Literacy for Middle School Students

Scientific literacy reflects “a broad and functional understanding of science for general education purposes” (DeBoer, 2000, p. 594). Herein, we present the ongoing development of the Scientific Literacy Assessment (SLA), a work‐in‐progress measure to assess middle school students\u27 (ages 11–14) scientific literacy. The SLA includes a selected response measure of students’ demonstrated scientific literacy (SLA‐D) and a motivation and beliefs scale based on existing measures of self‐efficacy, subjective task value, and personal epistemology for science (SLA‐MB). Our theoretical conceptualization of scientific literacy guided the development of our measure. We provide details from three studies: Pilot Study 1 (n = 124) and Pilot Study 2 (n = 220) describe the development of the SLA‐D by conducting iterative item analyses of the student responses, think‐aloud interviews with six students, and external expert feedback on the items in the SLA‐D. Study 3 describes the testing of our prototype measure (n = 264). We present a validity argument including reliability evidence that supports the use of the current version of the SLA to provide an evaluation of middle school students’ scientific literacy. Our resulting SLA includes the SLA‐D in two versions, each with 26 items and the SLA‐MB with 25 items across three scales: value of science, scientific literacy self‐efficacy, and personal epistemology

La bibliothèque en 8 questions… à Lucien Suel, Jean-Marc Flahaut, Fanny Chiarello et Carole Fives

Quatre écrivains aux univers singuliers plongent au cœur de leur rapport à la bibliothèque. Ils disent beaucoup de nous, et d’eux davantage encore

Exploring the Utility of the Simple View of Reading in Irish Children Attending Schools in Areas Designated as Socially Disadvantaged

Evidence suggests that children living in areas designated as socially disadvantaged may be at risk for literacy difficulties. The Simple View of Reading (Gough & Tunmer, 1986; Hoover &Gough, 1986) is a theoretical model that sets out to describe the processes that children need to develop to become proficient readers, that is word recognition or decoding processes and language comprehension processes. The overall aim of this study was to investigate the utility of the Simple View of Reading in a cohort of Irish children attending schools designated as socially disadvantaged. The objectives were twofold. The first objective was to investigate predictors of reading accuracy, spelling and reading comprehension skills in this sample. The second objective was to investigate whether or not these predictors varied with age. The sample comprised fifty-nine children attending two schools. Inclusion criteria were: children between the ages of 5-8 years; a sample of children within three ranges of reading abilities as rated by their teachers (teachers were asked to rate the children’s reading ability as above average, average or below average); and a minimum score of 80 on the British Picture Vocabulary Scales (BPVS) (Dunn et al., 1997) to be included. Reading accuracy (single word reading and passage reading), reading comprehension, and spelling were measured using three standardised tests i.e., Weschler Individual Attainment Test 11UK, Teachers Version (WIAT, 11UK-T) (Weschler, 2006), the York Assessment of Reading for Comprehension (YARC) (Snowling et al., 2009), and the Single Word Spelling Test (SWST), (Sacre & Masterson, 2000). Potential predictors of literacy skills, such as phonemic awareness and phonic knowledge skills, were measured using criterion-referenced tests. Vocabulary was also a potential predictor and was measured using the BPVS. There was mixed evidence for the Simple View of Reading. While phonic knowledge, phonemic knowledge and non-word reading were predictors of reading, other factors such as vocabulary were also predictors. Although vocabulary was a predictor of reading comprehension for the total sample, the picture was less clear when the effect of age was explored. To conclude, there was mixed evidence to support the Simple View of Reading.  Nonetheless, the findings were encouraging in that children were acquiring literacy skills

The feeding relationships of a small demersal fish community in the western Irish Sea

The feeding relationships of seasonal and resident fishes captured on a sandy substratum in the lrish Sea, in June and in September, were investigated. Stomach content analysis of the 17 species examined indicated four main feeding tvpes in the June sample and three in the September sample. The majority of the species analysed in both June and September showed the same food preferences in both months. Most of the fish species showed some changes in diet with increasing length (ontogenetic shift) - some became more specialized and others favoured more varied diet. There was no evidence of competition between specialist feeders within size groups