Workshop
· Physalia Courses · Online · 10 Feb 2025 · 5 days
Co-instructor with Dr. Alfredo Sánchez-Tójar
Meta-analysis in R
Evidence synthesis includes systematic reviews, meta-analyses, and other forms of evidence such as systematic maps or research weaving that allow us to summarize knowledge. When preceded by a systematic review, meta-analysis is a powerful statistical tool for quantitatively integrating findings across studies to (1) test overall effects and their generalizability, (2) understand context-dependencies, and (3) generate and test second-order hypotheses. Systematic reviews and meta-analyses have become a standard approach for qualitatively and quantitatively synthesizing evidence across fields, and their use has increased exponentially in the last decade. This course will provide a hands-on overview and introduction to modern methods for evidence synthesis, with a special focus on systematic review and meta-analysis in ecology and evolution.
We will begin with a detailed overview of the systematic review approach, focusing on question formation, systematic searching and study screening. Next, we will focus on the meta-analytic process, specifically on effect size choice, data extraction, data analysis, and importantly, result interpretation. We will make use of multilevel meta-analysis and meta-regression, with an introduction on how to account for phylogeny when multiple species are synthesised. Since meta-analytic results cannot be interpreted without a deep understanding of heterogeneity and publication bias, we will cover in detail how to estimate, adjust for, and interpret heterogeneity and publication bias.
This course will include a mix of lectures and hands-on exercises using real meta-analytic datasets. The emphasis throughout the course is on the application of the various methods and the interpretation of the results using the free software R and the R packages ‘metafor’ (Viechtbauer 2010) and ‘orchaRd’ (Nakagawa et al. 2023). The course will follow the principles of open science, with a strong focus on the importance of adhering to preferred reporting items for systematic reviews and meta-analyses in ecology and evolutionary biology (PRISMA EcoEvo; O’Dea et al. 2021). Throughout, we will consider examples of how to interpret results and present them using tables and data visualization, and for each step, we will provide literature and practical resources (e.g., R scripts).
More details about the workshop can be found here:
Meta-analysis in R
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