title: Representative samples.
authors.affiliation: Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: M
authors.initials: M
authors.lastname: Pagano
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods; D006801:Humans; D015983:Selection Bias; D013223:Statistics as Topic / Q000379:methods