efficacy

== English == === Etymology === From Old French efficace, from Late Latin efficācia (“efficacy”), from efficāx (“efficacious”); see efficacious. === Pronunciation === (Received Pronunciation, General American, Canada) IPA(key): /ˈɛf.ɪ.kə.si/ (General Australian) IPA(key): /ˈef.ɪ.kə.si/, (cultivated) [ˈef.ɪ.kə.sɪi] (New Zealand) IPA(key): /ˈef.ə.kə.si/ === Noun === efficacy (usually uncountable, plural efficacies) The ability to produce a desired effect under ideal testing conditions. 2005, Flay et al. Standards of Evidence: Criteria for Efficacy, Effectiveness and Dissemination DOI: 10.1007/s11121-005-5553-y Efficacy refers to the beneficial effects of a program or policy under optimal conditions of delivery, whereas effectiveness refers to effects of a program or policy under more real-world conditions. A degree of ability to produce a desired effect; effectiveness. 1996, Moskovich, Patent application PCT/US1996/003658 Toothbrush with improved efficacy ==== Synonyms ==== efficacity ==== Derived terms ==== ==== Related terms ==== ==== Translations ==== === Further reading === “efficacy”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC. William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “efficacy”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.