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Compound Evidence InstituteEvidence synthesis · established 2023Graded assessments of compounds, trials, methods and supply
Document set current to 30 July 2026
Defined term · Statistics and inference

I-squared

The proportion of observed variation across studies attributable to heterogeneity rather than to chance. Does not indicate whether the heterogeneity matters, and takes low values when studies are…

Document identifier
CEI-GT-074
Series
Defined term
Version
1.0
Published
30 Jul 2026
Last reviewed
30 Jul 2026
Certainty
Not rated

§1I-squared

§1.2Category

Statistics and inference — Terms describing how effects are estimated and how uncertainty is expressed.

§1.3Related terms

  • Heterogeneity — Variation in effect estimates across studies beyond that expected from chance. Quantified imperfectly by the I-squared statistic and assessed by inspection of the…
Compound Evidence Institute · CEI-GT-074 · https://compoundevidence.com/glossary/i-squared/ · retrieved 30 July 2026
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