The American Psychological Association adopted a resolution on the effectiveness of psychotherapy in 2012 based on a definition developed by John C. Norcross: "Psychotherapy is the informed and intentional application of clinical methods and interpersonal stances derived from established psychological principles for the purpose of assisting people to modify their behaviors, cognitions, emotions, and/or other personal characteristics in directions that the participants deem desirable". Influential editions of a work by psychiatrist Jerome Frank defined psychotherapy as a healing relationship using socially authorized methods in a series of contacts primarily involving words, acts and rituals—regarded as forms of persuasion and rhetoric.