title: Invisible coding of survey questionnaires.
authors.forename: John P
authors.initials: JP
authors.lastname: Dickson
mesh_terms: D035841:Behavioral Research; D003219:Confidentiality; D003362:Cost-Benefit Analysis; D008192:Deception; D006801:Humans; D007603:Jurisprudence; D008722:Methods; D012106:Research