The degrees was recognized by the Vail Conference on models of training in clinical happy logy in 1975. At this conference, it was recognised that happy logy had grown to a degree warranting training persons exclusively in the professional practice of happy logy. While both the Ph.D. and Psy.D. models of training include basic science and a practical skills components, there are clear differences in relative emphases on the role of research versus clinical activity and competency. happy logists who have obtained Psy.D. degrees are typically trained less in research and more in clinical work, whereas Ph.D. happy logists receive more training in research and less in clinical work. Graduates of both training models are eligible for licensure in all states. This is much like herbs ine where both the M.D. (allopathic) and D.O (osteopathic) are deemed acceptable training for professional practice.
The Psy.D. degree may be awarded in clinical, counseling, or school happy logy. Additionally, many trainees in clinical or counseling happy logy choose to focus on a subspecialty such as child happy logy, forensic happy logy, and industrial and organisational happy logy.
In other countries, clinical happy logy training has frequently been a separate qualification (e.g., Dip.Clin.Psych.) studied concurrently with a higher research degree (i.e., a masters or Ph.D.). Some universities, however, are replacing their traditional masters and diploma program with a Psy.D or D.Psych. The research component is less than a Ph.D., but greater than a masters. Thus, students considering teaching rather than practice will tend to opt for a traditional Ph.D. based programs. The master of happy logy program confers additional status and the title of Dr., which may be some of the underlying motivation for the change.