Doctor of Philosophy
A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: philosophiae doctor or doctor philosophiae) is the most common degree at the highest academic level, awarded following a course of study and research. The degree is abbreviated PhD and sometimes, especially in the U.S., as Ph.D. It is derived from the Latin Philosophiae Doctor, pronounced as three separate letters (/piːeɪtʃˈdiː/, PEE-aych-DEE).[1][2][3]
"PhD" redirects here. For other uses, see PHD (disambiguation).Type
3 to 8 years
Bachelor's degree
Master's degree
(varied by country and institution)
The abbreviation DPhil, from the English "Doctor of Philosophy",[4] is used by a small number of Commonwealth universities,[5] including the University of Oxford and formerly the University of York and University of Sussex in the United Kingdom.[6]
PhDs are awarded for programs across the whole breadth of academic fields. Since it is an earned research degree, those studying for a PhD are required to produce original research that expands the boundaries of knowledge, normally in the form of a dissertation, and defend their work before a panel of other experts in the field. The completion of a PhD is typically required for employment as a university professor, researcher, or scientist in many fields.[7]
History[edit]
Medieval and early modern Europe[edit]
In the universities of Medieval Europe, study was organized in four faculties: the basic faculty of arts, and the three higher faculties of theology, medicine, and law (canon law and civil law). All of these faculties awarded intermediate degrees (bachelor of arts, of theology, of laws, of medicine) and final degrees. Initially, the titles of master and doctor were used interchangeably for the final degrees—the title Doctor was merely a formality bestowed on a Teacher/Master of the art—but by the late Middle Ages the terms Master of Arts and Doctor of Theology/Divinity, Doctor of Law, and Doctor of Medicine had become standard in most places (though in the German and Italian universities the term Doctor was used for all faculties).[15]
The doctorates in the higher faculties were quite different from the current PhD degree in that they were awarded for advanced scholarship, not original research. No dissertation or original work was required, only lengthy residency requirements and examinations. Besides these degrees, there was the licentiate. Originally this was a license to teach, awarded shortly before the award of the master's or doctoral degree by the diocese in which the university was located, but later it evolved into an academic degree in its own right, in particular in the continental universities.
According to Keith Allan Noble (1994), the first doctoral degree was awarded in medieval Paris around 1150.[16] The doctorate of philosophy developed in Germany as the terminal teacher's credential in the 17th century (circa 1652).[17] There were no PhDs in Germany before the 1650s (when they gradually started replacing the MA as the highest academic degree; arguably, one of the earliest German PhD holders is Erhard Weigel (Dr. phil. hab., Leipzig, 1652).
The full course of studies might, for example, lead in succession to the degrees of Bachelor of Arts, Licentiate of Arts, Master of Arts, or Bachelor of Medicine, Licentiate of Medicine, or Doctor of Medicine, but before the early modern era, many exceptions to this existed. Most students left the university without becoming masters of arts, whereas regulars (members of monastic orders) could skip the arts faculty entirely.[18][19][20]
Educational reforms in Germany[edit]
This situation changed in the early 19th century through the educational reforms in Germany, most strongly embodied in the model of the University of Berlin, founded and controlled by the Prussian government in 1810. The arts faculty, which in Germany was labelled the faculty of philosophy, started demanding contributions to research,[21] attested by a dissertation, for the award of their final degree, which was labelled Doctor of Philosophy (abbreviated as Ph.D.)—originally this was just the German equivalent of the Master of Arts degree. Whereas in the Middle Ages the arts faculty had a set curriculum, based upon the trivium and the quadrivium, by the 19th century it had come to house all the courses of study in subjects now commonly referred to as sciences and humanities.[22] Professors across the humanities and sciences focused on their advanced research.[23] Practically all the funding came from the central government, and it could be cut off if the professor was politically unacceptable.[24]
These reforms proved extremely successful, and fairly quickly the German universities started attracting foreign students, notably from the United States. The American students would go to Germany to obtain a PhD after having studied for a bachelor's degree at an American college. So influential was this practice that it was imported to the United States, where in 1861 Yale University started granting the PhD degree to younger students who, after having obtained the bachelor's degree, had completed a prescribed course of graduate study and successfully defended a thesis or dissertation containing original research in science or in the humanities.[25] In Germany, the name of the doctorate was adapted after the philosophy faculty started being split up − e.g. Dr. rer. nat. for doctorates in the faculty of natural sciences − but in most of the English-speaking world the name "Doctor of Philosophy" was retained for research doctorates in all disciplines.
The PhD degree and similar awards spread across Europe in the 19th and early 20th centuries. The degree was introduced in France in 1808, replacing diplomas as the highest academic degree; into Russia in 1819, when the Doktor Nauk degree, roughly equivalent to a PhD, gradually started replacing the specialist diploma, roughly equivalent to the MA, as the highest academic degree; and in Italy in 1927, when PhDs gradually started replacing the Laurea as the highest academic degree.
Value and criticism[edit]
A career in academia generally requires a PhD, although in some countries it is possible to reach relatively high positions without a doctorate. In North America, professors are increasingly being required to have a PhD, and the percentage of faculty with a PhD may be used as a university ratings measure.[42]
The motivation may also include increased salary, but in many cases, this is not the result. Research by Bernard H. Casey of the University of Warwick, U.K, suggests that, over all subjects, PhDs provide an earnings premium of 26% over non-accredited graduates, but notes that master's degrees already provide a premium of 23% and a bachelor's 14%. While this is a small return to the individual (or even an overall deficit when tuition and lost earnings during training are accounted for), he claims there are significant benefits to society for the extra research training.[43]
However, some research suggests that overqualified workers are often less satisfied and less productive at their jobs.[44] These difficulties are increasingly being felt by graduates of professional degrees, such as law school, looking to find employment. PhD students may need to take on debt to undertake their degree.[45][46]
A PhD is also required in some positions outside academia, such as research jobs in major international agencies. In some cases, the Executive Directors of some types of foundations may be expected to hold a PhD. A PhD is sometimes felt to be a necessary qualification in certain areas of employment, such as in foreign policy think-tanks: U.S. News & World Report wrote in 2013 that "[i]f having a master's degree at the minimum is de rigueur in Washington's foreign policy world, it is no wonder many are starting to feel that the PhD is a necessary escalation, another case of costly signaling to potential employers".[47] Similarly, an article on the Australian public service states that "credentialism in the public service is seeing a dramatic increase in the number of graduate positions going to PhDs and masters degrees becoming the base entry level qualification".[48]
The Economist published an article in 2010 citing various criticisms against the state of PhDs. These included a prediction by economist Richard B. Freeman that, based on pre-2000 data, only 20% of life science PhD students would gain a faculty job in the U.S., and that in Canada 80% of postdoctoral research fellows earned less than or equal to an average construction worker ($38,600 a year). According to the article, only the fastest developing countries (e.g. China or Brazil) have a shortage of PhDs.[44] In 2022, Nature reported that PhD students' wages in biological sciences in the US do not cover living costs.[49]
The U.S. higher education system often offers little incentive to move students through PhD programs quickly and may even provide incentive to slow them down. To counter this problem, the United States introduced the Doctor of Arts degree in 1970 with seed money from the Carnegie Foundation for the Advancement of Teaching. The aim of the Doctor of Arts degree was to shorten the time needed to complete the degree by focusing on pedagogy over research, although the Doctor of Arts still contains a significant research component. Germany is one of the few nations engaging these issues, and it has been doing so by reconceptualising PhD programs to be training for careers, outside academia, but still at high-level positions. This development can be seen in the extensive number of PhD holders, typically from the fields of law, engineering, and economics, at the very top corporate and administrative positions. To a lesser extent, the UK research councils have tackled the issue by introducing, since 1992, the EngD.
Mark C. Taylor opined in 2011 in Nature that total reform of PhD programs in almost every field is necessary in the U.S. and that pressure to make the necessary changes will need to come from many sources (students, administrators, public and private sectors, etc.).[50] Other articles in Nature have also examined the issue of PhD reform.[51][52][53]
Freeman Dyson, professor emeritus at the Institute for Advanced Study in Princeton, was opposed to the PhD system and did not have a PhD degree.[54] On the other hand, it was understood by all his peers that he was a world leading scientist with many accomplishments already under his belt during his graduate study years and he was eligible to gain the degree at any given moment.
Models of supervision[edit]
At some universities, there may be training for those wishing to supervise PhD studies. There is much literature available, such as Delamont, Atkinson, and Parry (1997). Dinham and Scott (2001) have argued that the worldwide growth in research students has been matched by the increase in the number of what they term "how-to" texts for both students and supervisors, citing examples such as Pugh and Phillips (1987). These authors report empirical data on the benefits to a PhD candidate from publishing; students are more likely to publish with adequate encouragement from their supervisors.
Wisker (2005) has reported that research into this field distinguishes two models of supervision:
The technical-rationality model of supervision, emphasising technique; and the negotiated order model, which is less mechanistic, emphasising fluid and dynamic change in the PhD process. These two models were first distinguished by Acker, Hill and Black (1994; cited in Wisker, 2005). Considerable literature exists on the expectations that supervisors may have of their students (Phillips & Pugh, 1987) and the expectations that students may have of their supervisors (Phillips & Pugh, 1987; Wilkinson, 2005) in the course of PhD supervision. Similar expectations are implied by the Quality Assurance Agency's Code for Supervision (Quality Assurance Agency, 1999; cited in Wilkinson, 2005).
PhD in the workforce[edit]
PhD graduates represent a relatively small, elite group within most countries — around 1.1% of adults among OECD countries.[159] Slovenia, Switzerland and Luxembourg have higher numbers of PhD Graduates per capita as illustrated here. For Slovenia, this is because MSc degrees before Bologna Process are ranked at the same level of education as PhD. Without the MSc, Slovenia has 1.4% PhD graduates, which is comparable to the average in OECD and EU-23 countries.[160]