Dr William Glasser was the developer of Reality Therapy and Choice Theory. He was also notable for applying his theories to broader social issues, such as education, management, and marriage, to name a few.
Robert E. Wubbolding, EdD, is an internationally known teacher, author and practitioner of Reality Therapy has taught Choice Theory and Reality Therapy in the United States, Europe, Asia, and the Middle East. His contributions to the theory and practice include the ideas of "Positive Symptoms," "The Cycle of Counseling," "Five Levels of Commitment," and others.

Leon Lojk, psychologist, psychotherapist, senior instructor at William Glasser Institute, and a founder of the Training Centre for Choice Theory and Reality Therapy in Slovenia (in 1996) established the evidence that Choice Theory Psychology as well as Reality Therapy has its foundations in science and philosophy.

Boba Lojk, social worker, psychotherapist, senior instructor at William Glasser Institute, EART general secretary and confounder of Training Centre for Choice Theory and Reality Therapy in Slovenia that in 2009 became the European Institute for Reality Therapy (EIRT). Her contribution is that EIRT in 2011 has been recognized by EAP as The European Accredited Psychotherapy Training Institute (EAPTI). Thanks to this recognition as EAPTI every student who becomes RT psychotherapist through EIRT’s program automatic gets European Certificate for Psychotherapy (ECP) through direct award by EAP.