The term 'professional doctorate' is itself a matter of debate. These doctorates can also be referred to as taught, by practice or industrial.
There are broadly two types of 'professional' doctorates:
1) Those providing qualifications for professional registration
Numerous fields of study, notably (but not exclusively) medicine and allied health professions have professional doctorates. For example; those working in dentistry, optometry, pharmacy, psychology, physical therapy, occupational therapy, and health science usually require such degrees for professional registration.
2) Those which are a professional development qualification
A professional development qualification will provide the holder with the ability to apply for more senior positions in their field, as well as in academia, but is not necessarily required for professional registration such as Doctorate of Education (EdD).
Professional doctorates have been around in the UK since the early 1990s, although some more established doctoral programmes have also been brought under the professional doctorate umbrella. The aim of these programmes is to find novel approaches to integrating professional and academic knowledge. According to the UK Economic & Social Research Council (ESRC), students undertaking a professional doctorate are expected to:
".... make a contribution to both theory and practice in their field, and to develop professional practice by making a contribution to (professional) knowledge."
There is a good definition comparing industrial PhDs and EngD on the website of the Centre for Innovation Manufacturing in Composites at the University of Nottingham:
“PhD research can vary from abstract/theoretical to applied industry research. EngD research usually concerns a topic related to the business activities of the industrial sponsor. All time spent on EngD programmes are recognised by relevant institutions as contributing towards Chartered Engineer (CEng) status.”
The EngD is mainly a UK doctorate, but there are similar doctorates such as the European Industrial Doctorate (funded by the European Commission Marie Curie Actions). EIDs are joint-doctoral training projects between an academic participant and a company established in two different EU Member States.
Creative PhDs can be awarded by practice, portfolio or composition in disciplines which include music, film, theatre, architecture or design. These degrees are called 'Doctor of Arts' in the USA and Canada.
They generally carry additional requirements (University of East Anglia definition):
- The quality of the candidate's practice as submitted.
- The merit of the associated written commentary.
- The candidate's critical understanding of wider contexts for their practice, including creative, curatorial, educational, media studies, or film and TV business contexts; whether contemporary or historical.
- The original contribution made by the submission both to an enhanced professional practice by the candidate and to its wider context in practice-based research and theory.