Michael A. Seaman

A controlled, powerful multiple-comparison strategy for several situations.

The multiple-comparison procedure originally proposed by R. A. Fisher (1935) for the 1-way analysis of variance context has several desirable properties when K (the number of groups) is equal to 3. In this article, the logic of the procedure is described in conjunction with those properties. A discussion follows of how the Fisher procedure can be similarly applied in a number of other K=3 (and, more generally, 2-degree-of-freedom) hypothesis-testing situations. Finally, the Fisher logic is combined with recent sequential applications of the Bonferroni inequality to illustrate the utility and versatility of that combination for the applied researcher

The Effect of Time Constraints and Statistics Test Anxiety on Test Performance in a Statistics Course

Abstract The performance of students who completed a statistics examination under time limits was compared with that of students under no time limits. Another purpose of the study was to determine whether students high or low in statistics test anxiety were affected differentially by these two examination conditions. Twenty-six graduate students who were enrolled in an intermediate-level statistics course were randomly assigned to the two examination groups, timed or untimed. Both low- and high-anxious students performed better on the final course examination under the untimed condition than under the timed condition. However, the benefit of the untimed examination was greater for high-anxious students than for low-anxious students. The results were interpreted using Hills (1984) and Wines (1980) conceptual frameworks. The results suggest that differences between high- and low-anxious students in evaluative situations are caused by differences between them in motivational disposition and attentional focus.

WRITING IN THE SECONDARY FOREIGN LANGUAGE CLASSROOM: THE EFFECTS OF PROMPTS AND TASKS ON NOVICE LEARNERS OF FRENCH

This study investigated the effects of 3 different writing tasks (descriptive, narrative, and expository) and 3 different writing prompts (bare, vocabulary, and prose model) on 937 writing samples culled from 330 novice learners enrolled in 15 classes of Levels 1 and 2 high school French. In order to assess the quality, fluency, syntactic complexity, and accuracy of the writing samples, the researchers employed 4 evaluation methods: holistic scoring, length of product, mean length of T-units, and percentage of correct T-units. Results indicate that the descriptive task was the easiest and the expository task the most difficult. The prose model prompts produced the highest mean scores, and the bare prompts produced the lowest mean scores. Based on these findings, the researchers question whether the description of a novice writer in the ACTFL Proficiency Guidelines(1986) should be used as a blueprint for curriculum development and textbook construction for secondary novice foreign language learners.

The Impact of Literacy Coaches on Teachers' Beliefs and Practices

The field of literacy education has long been concerned with the question of how to help classroom teachers improve their practices so that students will improve as readers. Although there is consensus on what characterizes effective professional development, the reading research on which this consensus is based most often is small scale and involves direct support provided by university faculty. The South Carolina Reading Initiative is an exception: It is a statewide, site-based, large-scale staff development effort led by site-selected literacy coaches. Although university faculty provide long-term staff development to the coaches, the faculty are not directly involved with the professional development provided to teachers. In this study we sought to understand whether site-based, site-chosen literacy coaches could help teachers’ beliefs and practices become more consistent with what the field considers to be best practices. To understand teacher change, we used two surveys (Theoretical Orientation to Reading Profile, n = 817; South Carolina Reading Profile, n = 1,005) and case study research (n = 39) to document teachers’ beliefs and practices. We also had access to a state department survey (n = 1,428). Across these data, we found that teachers’ beliefs and practices became increasingly consistent with best practices as defined by standards set by the South Carolina State Department of Education, standards that were consistent with national standards. This suggests that large-scale staff development can affect teachers when the providers are site-based, site-selected literacy coaches.

A Comparison of the Exact Kruskal-Wallis Distribution to Asymptotic Approximations for All Sample Sizes up to 105

The authors generated exact probability distributions for sample sizes up to 35 in each of three groups (n ≤ 105) and up to 10 in each of four groups (n ≤ 40). They compared the exact distributions to the chi-square, gamma, and beta approximations. The beta approximation was best in terms of the root mean square error. At specific significance levels, either the gamma or beta approximation was best. These results suggest that the most common approximation, the chi-square approximation, is not a good choice. The authors demonstrate this point using an applied example. Critical value tables for the exact distribution are available online at http://faculty.virginia.edu/kruskal-wallis. The portion of these tables that provides critical values for equal sample sizes appears in this article. The authors recommend that researchers use critical values from the exact distribution whenever possible. If sample sizes exceed those included in the authors’ exact probability tables, they recommend using the beta approximation instead of the chi-square and gamma approximations.

Metaphors and Learning New Text

In this study, we investigated the influence of metaphors on text processing. Sixty-two graduate students were randomly assigned to three conditions that varied in the degree of explicitness provided between a metaphor and new information, both presented in the text. Differences in comprehension and overall number of ideas recalled were trivial among the three groups. In addition, there was a lack of total change in recall over time. However, a significant effect was found for the time by group interaction. In addition, both type of idea (main and minor, and metaphoric-linked and non-linked) by group interactions were significant, with the metaphor groups recalling more. Text supplements, such as metaphors, can direct the readers attention to certain types of ideas.

Pairwise Comparisons for Proportions: A Note on Cox and Key

This article focuses on a large-sample post hoc procedure for pairwise comparisons of proportions that was recently proposed by Cox and Key in 1993. Problems with the procedure are discussed, and a correct procedure is described. The method is then extended to planned comparisons of proportions.

Interrater Agreement on the Visual Analysis of Individual Tiers and Functional Relations in Multiple Baseline Designs

Previous research on visual analysis has reported low levels of interrater agreement. However, many of these studies have methodological limitations (e.g., use of AB designs, undefined judgment task) that may have negatively influenced agreement. Our primary purpose was to evaluate whether agreement would be higher than previously reported if we addressed these weaknesses. Our secondary purposes were to investigate agreement at the tier level (i.e., the AB comparison) and at the functional relation level in multiple baseline designs and to examine the relationship between raters’ decisions at each of these levels. We asked experts (N = 52) to make judgments about changes in the dependent variable in individual tiers and about the presence of an overall functional relation in 31 multiple baseline graphs. Our results indicate that interrater agreement was just at or just below minimally adequate levels for both types of decisions and that agreement at the individual tier level often resulted in agreement about the overall functional relation. We report additional findings and discuss implications for practice and future research.

Project ReSpecT: Toward an Evidence-Based Mentoring Model for Induction Teachers

School districts have struggled with special education teacher shortages for over a decade. Special education teachers who leave the profession after a few years certainly contribute to the shortage. Project ReSpecT (Retaining Special Education Teachers) was a federally funded project to develop and implement a mentoring model designed to retain 1st-year special education teachers. The purpose of this article is to describe the first two phases of Project ReSpecT, including the research that led to the development of the model and the pilot test phase. We also discuss the preliminary findings from this study in the context of results from similar programs. We end by discussing implications for educational policy and practice for mentoring models.

An evaluation of the agreement between the conservative dual-criterion method and expert visual analysis: AGREEMENT BETWEEN CDC AND VISUAL ANALYSIS

The conservative dual-criterion (CDC) method was developed to standardize the analysis of single-subject experimental designs data, but to date its accuracy has been evaluated only by comparing results to the statistical parameters of graphs. Our study investigated agreement between expert visual analysts and the CDC method on 66 AB tiers from published multiple baseline graphs. We found strong agreement between the two methods for certain types of graphs and discuss implications of the findings and areas for future research.