The MI therapist does this by facilitating the client's identification of the disadvantages of the status quo (their current problematic behavior), and eliciting statements about the advantages of changing behaviors.  The MI therapist also facilitates the client's self-efficacy  and expressions of intention to change.

Rollnick and Miller have chosen a peculiar name for this form of therapy.  The word "motivation" needs no explanation, but why did they choose the word "interviewing"?  They state that the word "interviewing" has "more of an egalitarian, sometimes even subordinate sense to the word."  The root of the word suggests "looking at something together."  This reflects their Rogerian bent.  Miller and Rollnick view MI as "an evolution of the client-centered approach that Rogers developed."  (Many therapist who have adopted this method prefer to call it Motivational Enhancement Therapy.)

Carl R. Rogers (1902-1987) developed Person-Centered Therapy in the 1940's.  Person-Centered Therapy is based on the premise that a client's mental health will improve organically in the setting of a therapuetic relationship that is empathic, non-judgmental, and characterized by unconditional positive regard.  Trust and caring are fundamental to Rogers' therapy who was raised in a strict Christian home.  His theory of personhood is diametrically opposed to behaviorism, believing that each person has  a creative power, a crucial force, that is not deterministically a product of heredity and upbringing,  i.e., a conditioned, mechanistic response to the environment.

Miller and Rollnick build on Roger's humanistic model, only making one major correction:  As stated above, MI is directive.  The therapist respects the client's perspective and experiences, resisting the imposition of his/her own goals upon the client.  The client remains autonomous.  However, with MI, the therapist is directive, consciously eliciting statements from the client that are congruent with the client's stated goals and objectives.  The therapist draws out motivation from the client's own values.  The MI therapist evokes discrepancy in the client, a gap between their current behavior and their stated goals.

Motivation Interviewing has been proven  to be very successful in the treatment of addictive disorders.  It is more effective as individual treatment, and is especially effective in treating people of color.