title: Visual acuity: calculating appropriate averages.
abstract: Controversy surrounds the averaging of visual acuity scores. We examine this debate and provide a series of guidelines and worked examples to enable investigators to select an average (e.g. arithmetic mean, geometric mean, median) appropriate for their data.
authors.affiliation: Department of Ophthalmology, University of Birmingham, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Moseley
authors.forename: H S
authors.initials: HS
authors.lastname: Jones
mesh_terms: D006801:Humans; D012016:Reference Values; D013223:Statistics as Topic / Q000379:methods*; D014792:Visual Acuity