Evidence map›Paper›PMID 42693758›Full record

ArticleEcology letters2026

A New Effect Size for Meta-Analysis of Magnitude: lnM.

Shinichi Nakagawa, Ayumi Mizuno, Coralie Williams, Malgorzata Lagisz, Rose E O'Dea, Daniel W A Noble, Alistair M Senior, Erick Lundgren, Santiago Ortega

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Ecology letters, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Shinichi NakagawaCollaboration for Open Science and Synthesis in Ecology and Evolution (COSSEE), Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0002-7765-5182
Ayumi MizunoCollaboration for Open Science and Synthesis in Ecology and Evolution (COSSEE), Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0003-0822-5637
Coralie WilliamsEvolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia.ORCID https://orcid.org/0000-0003-1312-4953
Malgorzata LagiszCollaboration for Open Science and Synthesis in Ecology and Evolution (COSSEE), Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0002-3993-6127
Rose E O'DeaEvolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia.ORCID https://orcid.org/0000-0001-8177-5075
Daniel W A NobleDivision of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australia.ORCID https://orcid.org/0000-0001-9460-8743
Alistair M SeniorSchool of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia.ORCID https://orcid.org/0000-0001-9805-7280
Erick LundgrenCollaboration for Open Science and Synthesis in Ecology and Evolution (COSSEE), Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0001-9893-3324
Santiago OrtegaCollaboration for Open Science and Synthesis in Ecology and Evolution (COSSEE), Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0002-3518-276X

Funding

Australian Research Council FT220100276Australian Research Council FT230100240Canada Excellence Research Chairs, Government of Canada CERC-2022-00074Natural Sciences and Engineering Research Council of Canada RGPIN-2025-04813
6 · The paper itself

Abstract

Meta-analyses in ecology and evolution sometimes target the magnitude of differences between groups rather than their direction, for example, when the question concerns deviation from a biological optimum or divergence from a reference state. A common practice is to convert signed effects into magnitudes by taking absolute values, but this can induce upward distortion and non-normal sampling distributions under standard meta-analytic models. Here we introduce lnM, a log-ratio effect size for the magnitude of difference between two groups, defined from one-way ANOVA components. lnM is asymptotically normal, supports standard multilevel meta-analysis and meta-regression and applies to both ratio- and interval-scale traits. Using theory, simulations and worked examples, we show when delta-method and single-fit bootstrap estimators perform well, and how lnM can be used to assess publication bias.

Indexed as

EcologyMeta-Analysis as TopicModels, BiologicalBayes TheoremComputer SimulationBayesian statisticsbiological optimacoefficient‐of‐variation ratiolocation‐scale modelsmeta‐regression

Identifiers

PMID42693758
PMCPMC13542630

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.