General information

In the United States, first-professional doctoral degrees are first degrees in a given field and include: Chiropractic, Dentistry, Law, Medicine, Optometry, Osteopathy, Pharmacy, Physical Therapy, Podiatry, Psychology and Veterinary medicine. There are many others. Although these degrees may be both the initial and terminal degree in their field, students seeking to enter degree programs for them must have already completed a Bachelors degree, usually in a related field.

First-professional doctoral degrees such as the M.D. and J.D. do not require completion of a thesis/dissertation or publication of a coherent body of literature. The normal minimum term for a first-professional doctorate can be as little as 3 years past secondary education. These "first-professional" doctoral degrees therefore lack the status of the research doctorates. Actual practice within the field requires that the degree holder become licensed by the appropriate body (an organization not affiliated with the schools granting the degrees) and registration can require a certain amount of work experience.

The most common type of research doctorate is a Ph.D. (Philosophiae Doctor or Doctor of Philosophy), though there are many other designations, listed below.

Minimum periods for research doctorates vary considerably: In the UK and USA the minimum time for completing a Ph.D. is usually 3 years from time of enrollment (which usually takes place after the award of a bachelor's or master's degree). Although completions within this period are possible, most candidates take considerably longer, with a common average of roughly 7.5 years often seen in the USA for the 'hard' sciences, such as physics, engineering, and chemistry. A shorter span of time in the USA is often seen in the 'soft' sciences such as sociology and anthropology.

Although the Ph.D. is almost universally accepted currently as the standard qualification for an academic career, it is a relatively new invention. The older-style doctorates (now usually called "Higher Doctorates" in the United Kingdom) take much longer to complete, since candidates must show themselves to be leading experts in their subjects. These doctorates are now becoming rare, and are usually only awarded as Honorary degrees. In France, the higher doctorate was suppressed and replaced for academic recruitment purposes by the much lighter "habilitation to direct theses".