Olivia Parker, PhD

Academic Researcher and Evidence Synthesis Expert

Olivia Parker is an academic researcher and evidence synthesis expert specializing in systematic reviews and quantitative analysis. She has supported projects across healthcare, behavioral sciences, and public health, guiding clients through every stage of the research process. Olivia's work is grounded in evidence-based principles and a commitment to producing high-quality, reproducible research.

Areas of focus

Systematic review
Quantitative analysis
Evidence synthesis
Reproducible research
Public health research

How the analysis is checked

Every guide and tool Olivia reviews follows the standard methods set out in the Cochrane Handbook for Systematic Reviews of Interventions and in Borenstein, Hedges, Higgins, and Rothstein, Introduction to Meta-Analysis. The pooling behind our calculators is validated against the metafor package in R and statsmodels in Python, so the numbers line up with what a statistician reproduces by hand. You can read more about how we calculate and check every result.

Guides by Olivia Parker

June 5, 2026 · 8 minUnderstanding I-Squared and HeterogeneityWhat I-squared and statistical heterogeneity actually measure, how to read the thresholds, and what to do when between-study variation runs high.Read guide June 2, 2026 · 9 minFixed-Effect vs Random-Effects Meta-AnalysisHow the fixed-effect and random-effects models differ in their assumptions, weighting, pooled estimate, and confidence interval, and how to choose and defend one.Read guide May 19, 2026 · 8 minEffect Size and Cohen's d ExplainedWhat an effect size is, how Cohen's d standardizes a mean difference, what its benchmarks mean, and why meta-analysis pools effect sizes rather than p-values.Read guide May 5, 2026 · 8 minPublication Bias in Meta-AnalysisHow publication bias distorts a meta-analysis, the methods used to detect it, and the prospective registration and grey-literature searching that prevent it.Read guide

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