2,093 research outputs found
Without Supporting Statistical Evidence, Where Would Reported Measures of Substantive Importance Lead? To No Good Effect
Although estimating substantive importance (in the form of reporting effect sizes) has recently received widespread endorsement, its use has not been subjected to the same degree of scrutiny as has statistical hypothesis testing. As such, many researchers do not seem to be aware that certain of the same criticisms launched against the latter can also be aimed at the former. Our purpose here is to highlight major concerns about effect sizes and their estimation. In so doing, we argue that effect size measures per se are not the hoped-for panaceas for interpreting empirical research findings. Further, we contend that if effect sizes were the only basis for interpreting statistical data, social-science research would not be in any better position than it would if statistical hypothesis testing were the only basis. We recommend that hypothesis testing and effect-size estimation be used in tandem to establish a reported outcome’s believability and magnitude, respectively, with hypothesis testing (or some other inferential statistical procedure) retained as a “gatekeeper” for determining whether or not effect sizes should be interpreted. Other methods for addressing statistical and substantive significance are advocated, particularly confidence intervals and independent replications
The Composite Hypothesis Contrast Procedure: A Novel Sequential Multiple-Comparison Approach
The sequential composite hypothesis contrast multiple-comparison procedure is introduced for comparing two treatment conditions with one or two control conditions on one or two outcome measures. The procedure deserves consideration insofar as its power advantage over other commonly applied multiple-comparison methods can be sizable
The Trouble With Interpreting Statistically Nonsignificant Effect Sizes in Single-Study Investigations
In this commentary, we offer a perspective on the problem of authors reporting and interpreting effect sizes in the absence of formal statistical tests of their chanceness. The perspective reinforces our previous distinction between single-study investigations and multiple-study syntheses
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A metacognitive intervention for teaching fractions to students with or at-risk for learning disabilities in mathematics
Assessment data from the United States and international reports of student achievement indicate that upper elementary students are failing to meet basic levels of proficiency in fractions and writing, and that this is particularly prevalent with students with or at-risk for learning disabilities in mathematics. Proficiency with fractions has been identified as foundational for learning higher-level mathematics but remains one of the most difficult skills for students to learn. In addition, students' difficulty with fractions is exacerbated because of increased chances of comorbidity with language learning problems, particularly difficulties constructing arguments and communicating using writing. We describe FACT+(RC2)-C-2, a language-based, metacognitive instructional intervention that was designed using the Self-Regulated Strategy Development model (SRSD) for teaching foundational concepts of fractions. The results from two studies in which the intervention was administered to upper elementary students who exhibit mathematics difficulties indicated selected increases in students' computational accuracy, quality of mathematical reasoning, number of rhetorical elements, and total words. With evidence of improved performance in these areas, FACT+(RC2)-C-2 holds promise for helping these students become proficient self-regulated learners.12 month embargo; published online: 18 March 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
An Improved Two Independent-Samples Randomization Test for Single-Case AB-Type Intervention Designs: A 20-Year Journey
Detailed is a 20-year arduous journey to develop a statistically viable two-phase (AB) single-case two independent-samples randomization test procedure. The test is designed to compare the effectiveness of two different interventions that are randomly assigned to cases. In contrast to the unsatisfactory simulation results produced by an earlier proposed randomization test, the present test consistently exhibited acceptable Type I error control under various design and effect-type configurations, while at the same time possessing adequate power to detect moderately sized intervention-difference effects. Selected issues, applications, and a multiple-baseline extension of the two-sample test are discussed
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Can Middle-School Students Learn to Reason Statistically Through Simulation Activities?
This paper describes the implementation and quasiexperimental evaluation of a three-week instructional project designed in accordance with theories and assumptions of constructivism and socially situated cognition. Our goal was to develop students' ability to reason about real-life problems, where "good reasoning" was conceptualized in terms of a normative thinking model derived from cognitive research in decision making, probabilistic reasoning, and argumentation. In the spring of 1994, students in two middle school classrooms worked in teams that collected evidence, constructed arguments, and prepared presentations while engaged in activities that culminated in a mock legislative hearing. Through instruction and mentoring, students were encouraged to use statistics and probability as tools for reasoning. The effectiveness of the program was evaluated by comparing the written arguments of students from the two treatment classrooms with those of students from eight comparison classrooms. Students' arguments were scored in terms of how well they captured essential features of model reasoning and avoided particular thinking fallacies. That the reasoning abilities of students developed through social negotiation and shared problem solving was s
Improved Randomization Tests for a Class of Single-Case Intervention Designs
Forty years ago, Eugene Edgington developed a single-case AB intervention design-and-analysis procedure based on a random determination of the point at which the B phase would start. In the present simulation studies encompassing a variety of AB-type contexts, it is demonstrated that by also randomizing the order in which the A and B phases are administered, a researcher can markedly increase the procedure’s statistical power
Response of Coastal Fishes to the Gulf of Mexico Oil Disaster
The ecosystem-level impacts of the Deepwater Horizon disaster have been largely unpredictable due to the unique setting and magnitude of this spill. We used a five-year (2006–2010) data set within the oil-affected region to explore acute consequences for early-stage survival of fish species inhabiting seagrass nursery habitat. Although many of these species spawned during spring-summer, and produced larvae vulnerable to oil-polluted water, overall and species-by-species catch rates were high in 2010 after the spill (1,989±220 fishes km-towed−1 [μ ± 1SE]) relative to the previous four years (1,080±43 fishes km-towed−1). Also, several exploited species were characterized by notably higher juvenile catch rates during 2010 following large-scale fisheries closures in the northern Gulf, although overall statistical results for the effects of fishery closures on assemblage-wide CPUE data were ambiguous. We conclude that immediate, catastrophic losses of 2010 cohorts were largely avoided, and that no shifts in species composition occurred following the spill. The potential long-term impacts facing fishes as a result of chronic exposure and delayed, indirect effects now require attention
Major Radiodiagnostic Imaging in Pregnancy and the Risk of Childhood Malignancy: A Population-Based Cohort Study in Ontario
In a record-linkage study, Joel Ray and colleagues examine the association between diagnostic imaging during pregnancy and later childhood cancers
Patents and Industrialisation. An Historical Overview of the British Case, 1624-1907
A Report to the Strategic Advisory Board on Intellectual Property Policy (SABIP), U
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