Scatter plot of effect size against study precision, used to visually screen for publication bias.
A funnel plot plots individual trial effect estimates against a measure of their precision (e.g., standard error), with symmetry expected around the pooled effect if no bias is present. Asymmetry can suggest publication bias or small-study effects, though genuine heterogeneity between trials can also produce an asymmetric pattern, so it is usually interpreted alongside a formal statistical test.
This guide was auto-drafted and is pending editorial review.