We need to make substantial changes to how we conduct research. First, in response to heightened concern that our published research literature is incomplete and untrustworthy, we need new requirements to ensure research integrity. These include prespecification of studies whenever possible, avoidance of selection and other inappropriate data- analytic practices, complete reporting, and encouragement of replication. Second, in response to renewed recognition of the severe flaws of null-hypothesis significance testing (NHST), we need to shift from reliance on NHST to estimation and other preferred techniques. The new statistics refers to recommended practices, including estimation based on effect sizes, confidence intervals, and meta-analysis. The techniques are not new, but adopting them widely would be new for many researchers, as well as highly beneficial. This article explains why the new statistics are important and offers guidance for their use. It describes an eight-step new-statistics strategy for research with integrity, which starts with formulation of research questions in estimation terms, has no place for NHST, and is aimed at building a cumulative quantitative discipline.

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The New Statistics Why and How

This handbook presents guidelines for synthesizing findings of qualitative research.After discussing the importance of such synthesis for building knowledge, in the second chapter the authors introduce definitions of and types of qualitative research synthesis.They view the synthesis as a study comprising a series of steps, starting with the formulation of a problem and a statement of purpose. In chapter 3 the authors focus on the steps of retrieving all research reports and determining their relevance to the study domain. In chapter 4 they describe strategies for appraising individual study reports and for conducting a comparative appraisal. Comparative appraisal consists of displaying key elements of the studies included in the synthesis and comparing them in order to determine whether they confirm, extend, refute, or complement each other. In chapter 5 Sandelowski and Barroso discuss issues encountered in appraising the quality of qualitative studies and present a typology of findings that can be used to classify results. In chapters 6 and 7 they describe the process of implementing the two types of qualitative research synthesis, metasummary and metasynthesis. In chapter 8 the authors review strategies for maintaining validity of qualitative research synthesis and in chapter 9 they review content and format for presenting the results of the synthesis. Sandelowski and Barroso are to be commended for addressing a controversial topic, and for refining the types of qualitative research findings and procedures for conducting a synthesis of these findings.They clarify the arguments advanced by proponents and opponents of the qualitative research synthesis, thereby facilitating our understanding of the rationale underlying the two types of synthesis. Conceiving the synthesis as a study that is conducted in steps, similar to those entailed in a metaanalysis, helps us to view the process as a systematic one with a welldefined sequence of steps.The book is structured accordingly, starting with the formulation of a researchable problem, moving on to the conduct of an extensive search of the relevant literature, then to an appraisal and synthesis of findings across studies, and ending with CJNR 2008,Vol. 40 No 3, 179 –180

https://cjnr.archive.mcgill.ca/article/download/2146/2140

Handbook for Synthesizing Qualitative Research

Service-learning is an experience-based approach to education and learning that has a set of diverse learning outcomes. Because of the uniqueness of its pedagogical approach and breadth of potential learning outcomes, management and business scholars have recognized its value. Much theory and supporting research has been generated on the effect of service-learning on college and university students. Through meta-analytic techniques, we found support for the hypotheses that service-learning has a positive effect on understanding of social issues (Est. .34); personal insight (Est. .28); and cognitive development (Est. .52). We also found significant moderating evidence for research design, type of reflection, type of measurement, and the service experience as optional or required. We conclude with a discussion of the theoretical and practical implications of these findings along with suggestions for future research.

A Meta-Analysis on the Effects of Service-Learning on the Social, Personal, and Cognitive Outcomes of Learning

The authors describe the relative benefits of conducting meta-analyses with (a) individual participant data (IPD) gathered from the constituent studies and (b) aggregated data (AD), or the group-level statistics (in particular, effect sizes) that appear in reports of a study's results. Given that both IPD and AD are equally available, meta-analysis of IPD is superior to meta-analysis of AD. IPD meta-analysis permits synthesists to perform subgroup analyses not conducted by the original collectors of the data, to check the data and analyses in the original studies, to add new information to the data sets, and to use different statistical methods. However, the cost of IPD meta-analysis and the lack of available IPD data sets suggest that the best strategy currently available is to use both approaches in a complementary fashion such that the first step in conducting an IPD meta-analysis would be to conduct an AD meta-analysis. Regardless of whether a meta-analysis is conducted with IPD or AD, synthesists must remain vigilant in how they interpret their results. They must avoid ecological fallacies, Simpson's paradox, and interpretation of synthesis-generated evidence as supporting causal inferences.

The Relative Benefits of Meta-Analysis Conducted With Individual Participant Data Versus Aggregated Data

The present article systematically reviews recent literature on the in vivo adaptation of asymptomatic human tendons following increased chronic mechanical loading, and meta-analyzes the loading conditions, intervention outcomes, as well as methodological aspects. The search was performed in the databases PubMed, Web of Knowledge, and Scopus as well as in the reference lists of the eligible articles. A study was included if it conducted (a) a longitudinal exercise intervention (≥8 weeks) on (b) healthy humans (18 to 50 years), (c) investigating the effects on mechanical (i.e., stiffness), material (i.e., Young’s modulus) and/or morphological properties (i.e., cross-sectional area (CSA)) of tendons in vivo, and was reported (d) in English language. Weighted average effect sizes (SMD, random-effects) and heterogeneity (Q and I
 2
 statistics) of the intervention-induced changes of tendon stiffness, Young’s modulus, and CSA were calculated. A subgroup analysis was conducted regarding the applied loading intensity, muscle contraction type, and intervention duration. Further, the methodological study quality and the risk of bias were assessed. The review process yielded 27 studies with 37 separate interventions on either the Achilles or patellar tendon (264 participants). SMD was 0.70 (confidence interval: 0.51, 0.88) for tendon stiffness (N=37), 0.69 (0.36, 1.03) for Young’s modulus (N=17), and 0.24 (0.07, 0.42) for CSA (N=33), with significant overall intervention effects (p<0.05). The heterogeneity analysis (stiffness: I
 2
 =30%; Young’s modulus: I
 2
 =57%; CSA: I
 2
 =21%) indicated that differences in the loading conditions may affect the adaptive responses. The subgroup analysis confirmed that stiffness adaptation significantly (p<0.05) depends on loading intensity (I
 2
 =0%), but not on muscle contraction type. Although not significantly different, SMD was higher for interventions with longer duration (≥12 weeks). The average score of 71±9% in methodological quality assessment indicated an appropriate quality of most studies. The present meta-analysis provides elaborate statistical evidence that tendons are highly responsive to diverse loading regimens. However, the data strongly suggests that loading magnitude in particular plays a key role for tendon adaptation in contrast to muscle contraction type. Furthermore, intervention-induced changes in tendon stiffness seem to be more attributed to adaptations of the material rather than morphological properties.

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Human tendon adaptation in response to mechanical loading: a systematic review and meta-analysis of exercise intervention studies on healthy adults

The need for research synthesis grows along with the volume of contemporary published scholarship. Reporting such synthesis warrants rigorous guidelines for preparing these important, information-rich documents that make statements concerning the state of knowledge about a topic, gaps in knowledge, or the aggregation or integration of primary research. Cooper’s revised and expanded fourth edition of Research Synthesis and MetaAnalysis: A Step-by-Step Approach (2010) provides these needed guidelines with special attention given to the threats to validity at all steps of the research synthesis process.

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Carla Hansen

Papers

More Tools for the Synthesist’s Toolbag in Harris Cooper’s Research Synthesis and Meta-Analysis: A Step-by-Step Approach (4th ed.)