A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin Philosophiae Doctor ) is the highest academic degree awarded by universities in many countries. Ph.D.s are awarded for programs across the whole breadth of academic fields. The completion of a Ph.D. is often a requirement for employment as a university professor, researcher, or scientist in many fields. Individuals who have earned a Doctor of Philosophy degree may, in most jurisdictions, use the title of " Doctor " (often abbreviated "Dr") or, in non-English speaking countries, variants such as "Dr. Phil." with their name, and may use post-nominal letters such as "Ph.D.", "PhD" (depending on the awarding institute). 
The requirements to earn a Ph.D. degree vary considerably according to the country, institution, and time period, from entry-level research degrees to higher doctorates. During the studies that lead to the degree, the student is called a doctoral student or Ph.D. student ; a student who has completed all of their coursework and comprehensive examinations and is working on their thesis /dissertation is sometimes known as a doctoral candidate or Ph.D. candidate (see: all but dissertation). A student attaining this level may be granted a Candidate of Philosophy degree at some institutions.
A Ph.D. candidate must submit a project, thesis or dissertation often consisting of a body of original academic research, which is in principle worthy of publication in a peer-reviewed journal.  In many countries, a candidate must defend this work before a panel of expert examiners appointed by the university. Universities sometimes award other types of doctorate besides the Ph.D., such as the Doctor of Musical Arts (D.M.A.) for music performers and the Doctor of Education (Ed.D.) for professional educators. In 2005 the European Universities Association defined the Salzburg Principles , ten basic principles for third-cycle degrees (doctorates) within the Bologna Process.  These were followed in 2016 by the Florence Principles , seven basic principles for doctorates in the arts laid out by the European League of Institutes of the Arts, which have been endorsed by the European Association of Conservatoires, the International Association of Film and Television Schools, the International Association of Universities and Colleges of Art, Design and Media, and the Society for Artistic Research. 
In the context of the Doctor of Philosophy and other similarly titled degrees, the term "philosophy" does not refer to the field or academic discipline of philosophy, but is used in a broader sense in accordance with its original Greek meaning, which is "love of wisdom". In most of Europe, all fields (history, philosophy, social sciences, mathematics, and natural philosophy / sciences) other than theology, law, and medicine (the so-called professional, vocational, or technical curriculum) were traditionally known as philosophy, and in Germany and elsewhere in Europe the basic faculty of liberal arts was known as the "faculty of philosophy".
The degree is abbreviated PhD (sometimes Ph.D. in North America), from the Latin Philosophiae Doctor , pronounced as three separate letters (/piːeɪtʃˈdiː/ ).    The abbreviation DPhil, from the English 'Doctor of Philosophy',  is used by a small number of British and Commonwealth universities, including Oxford and formerly York and Sussex, as the abbreviation for degrees from those institutions. 
Medieval and early modern Europe
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).
The doctorates in the higher faculties were quite different from the current Ph.D. 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 or doctor 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.  The doctorate of philosophy developed in Germany as the terminal Teacher's credential in the 17th century (c. 1652). 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).
In theory, 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, Doctor of Medicine. But before the early modern era, there were many exceptions to this. Most students left the university without becoming masters of arts, whereas regulars (members of monastic orders) could skip the arts faculty entirely.   
Educational reforms in Germany
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,  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.  Professors across the humanities and sciences focused on their advanced research.  Practically all the funding came from the central government, and it could be cut off if the professor was politically unacceptable. 
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 Ph.D. after having studied for a bachelor's degrees 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 Ph.D. 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.  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.
History in the United Kingdom
Research degrees first appeared in the UK in the late 19th century in the shape of the Doctor of Science (DSc or ScD) and other such "higher doctorates". The University of London introduced the DSc in 1860, but as an advanced study course, following on directly from the BSc, rather than a research degree. The first higher doctorate in the modern sense was Durham University's DSc, introduced in 1882.  This was soon followed by other universities, including the University of Cambridge establishing its ScD in the same year and the University of London transforming its DSc into a research degree in 1885. These were, however, very advanced degrees, rather than research-training degrees at the PhD level— Harold Jeffreys said that getting a Cambridge ScD was "more or less equivalent to being proposed for the Royal Society". 
Finally, in 1917 the current degree of Ph.D. was introduced, along the lines of the American and German model, and quickly became popular with both British and foreign students. The slightly older degrees of Doctor of Science and Doctor of Literature/Letters still exist at British universities; together with the much older degrees of Doctor of Divinity (DD), Doctor of Music (DMus), Doctor of Civil Law (DCL) and Doctor of Medicine (MD) they form the higher doctorates, but apart from honorary degrees they are only infrequently awarded.
It should be noted that in the English (but not the Scottish) universities the Faculty of Arts had become dominant by the early 19th century. Indeed, the higher faculties had largely atrophied, since medical training had shifted to teaching hospitals, the legal training for the common law system was provided by the Inns of Court (with some minor exceptions, see Doctors' Commons), and few students undertook formal study in theology. This contrasted with the situation in the continental European universities at the time, where the preparatory role of the Faculty of Philosophy or Arts was to a great extent taken over by secondary education: in modern France, the Baccalauréat is the examination taken at the end of secondary studies. The reforms at the Humboldt University transformed the Faculty of Philosophy or Arts (and its more recent successors such as the Faculty of Sciences) from a lower faculty into one on a par with the Faculties of Law and Medicine.
There were similar developments in many other continental European universities, and at least until reforms in the early 21st century many European countries (e.g. Belgium, Spain, and the Scandinavian countries) had in all faculties triple degree structures of bachelor (or candidate) − licentiate − doctor as opposed to bachelor − master − doctor; the meaning of the different degrees varied a lot from country to country however. To this day this is also still the case for the pontifical degrees in theology and canon law: for instance, in Sacred theology the degrees are Bachelor of Sacred Theology (STB), Licentiate of Sacred Theology (STL), and Doctor of Sacred Theology (STD), and in Canon law: Bachelor of Canon Law (JCB), Licentiate of Canon Law (JCL), and Doctor of Canon Law (JCD).
History in the United States
Until the mid-19th century, advanced degrees were not a criterion for professorships at most colleges. That began to change as the more ambitious scholars at major schools went to Germany for 1 to 3 years to obtain a Ph.D. in the sciences or humanities. Graduate schools slowly emerged in the United States. In 1861, Yale awarded the first three earned Ph.D.s in North America to Eugene Schuyler, Arthur Williams Wright, and James Morris Whiton,  although honorary Ph.D.s had been awarded in the U.S. for almost a decade, with Bucknell University awarding the first to Ebenezer Newton Elliott in 1852. 
In the next two decades, NYU, the University of Pennsylvania, Harvard, and Princeton also began granting the degree. Major shifts toward graduate education were foretold by the opening of Clark University in 1887, which only offered graduate programs and the Johns Hopkins University which focused on its Ph.D. program. By the 1890s, Harvard, Columbia, Michigan and Wisconsin were building major graduate programs, whose alumni were hired by new research universities. By 1900, 300 Ph.D.s were awarded annually, most of them by six universities. It was no longer necessary to study in Germany. However, half of the institutions awarding earned Ph.D.s in 1899 were undergraduate institutions that granted the degree for work done away from campus.  Degrees awarded by universities without legitimate Ph.D. programs accounted for about a third of the 382 doctorates recorded by the U.S. Department of Education in 1900, of which another 8–10% were honorary. 
At the start of the 20th century, U.S. universities were held in low regard internationally and many American students were still traveling to Europe for Ph.D.s. The lack of centralised authority meant anyone could start a university and award Ph.D.s. This led to the formation of the Association of American Universities by 14 leading research universities (producing nearly 90% of the approximately 250 legitimate research doctorates awarded in 1900), with one of the main goals being to "raise the opinion entertained abroad of our own Doctor's Degree". 
In Germany, the national government funded the universities and the research programs of the leading professors. It was impossible for professors who were not approved by Berlin to train graduate students. In the United States, by contrast, private universities and state universities alike were independent of the federal government. Independence was high, but funding was low. The breakthrough came from private foundations, which began regularly supporting research in science and history; large corporations sometimes supported engineering programs. The postdoctoral fellowship was established by the Rockefeller Foundation in 1919. Meanwhile, the leading universities, in cooperation with the learned societies, set up a network of scholarly journals. " Publish or perish " became the formula for faculty advancement in the research universities. After World War II, state universities across the country expanded greatly in undergraduate enrollment, and eagerly added research programs leading to masters or doctorate degrees. Their graduate faculties had to have a suitable record of publication and research grants. Late in the 20th century, "publish or perish" became increasingly important in colleges and smaller universities. 
Detailed requirements for the award of a Ph.D. degree vary throughout the world and even from school to school. It is usually required for the student to hold an Honours degree or a Master's Degree with high academic standing, in order to be considered for a Ph.D. program. In the US, Canada, India, and Denmark, for example, many universities require coursework in addition to research for Ph.D. degrees. In other countries (such as the UK) there is generally no such condition, though this varies by university and field.  Some individual universities or departments specify additional requirements for students not already in possession of a bachelor's degree or equivalent or higher. In order to submit a successful Ph.D. admission application, copies of academic transcripts, letters of recommendation, a research proposal, and a personal statement are often required. Most universities also invite for a special interview before admission.
A candidate must submit a project or thesis or dissertation often consisting of a body of original academic research, which is in principle worthy of publication in a peer-reviewed context.  In many countries a candidate must defend this work before a panel of expert examiners appointed by the university; in other countries, the dissertation is examined by a panel of expert examiners who stipulate whether the dissertation is in principle passable and any issues that need to be addressed before the dissertation can be passed.
A Ph.D. student or candidate is conventionally required to study on campus under close supervision. With the popularity of distance education and e-learning technologies, some universities now accept students enrolled into a distance education part-time mode.
In a " sandwich Ph.D." program, Ph.D. candidates do not spend their entire study period at the same university. Instead, the Ph.D. candidates spend the first and last periods of the program at their home universities, and in between conduct research at another institution or field research.  Occasionally a "sandwich Ph.D." will be awarded by two universities. 
A PhD confirmation is a preliminary presentation or lecture that a PhD candidate presents to faculty and possibly other interested members. The lecture follows after a suitable topic has been identified, and can include such matters as the aim of the research, methodology, first results, planned (or finished) publications, etc.
The confirmation lecture can be seen as a trial run for the final public defence, though faculty members at this stage can still largely influence the direction of the research. At the end of the lecture, the PhD candidate can be seen as "confirmed" – faculty members give their approval and trust that the study is well directed and will with high probability result in the candidate being successful.
In the United States, this is generally called advancing to Candidacy, the confirmation event being called the Candidacy Examination.
Value and criticism
Ph.D. students are often motivated to pursue the Ph.D. by scientific and humanistic curiosity, the desire to contribute to the academic community, service to others, or personal development. A career in academia generally requires a Ph.D., though, 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 Ph.D., because the percentage of faculty with a Ph.D. is used as a university ratings measure. 
The motivation may also include increased salary, but in many cases, this is not the result. Research by Casey suggests that, over all subjects, Ph.D.s provide an earnings premium of 26% over non-accredited graduates, but notes that master's degrees 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.  However, some research suggests that overqualified workers are often less satisfied and less productive at their jobs.  These difficulties are increasingly being felt by graduates of professional degrees, such as law school, looking to find employment. Ph.D. students often have to take on debt to undertake their degree.  
A Ph.D. 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 Ph.D. A Ph.D. is sometimes felt to be a necessary qualification in certain areas of employment, such as in foreign policy think-tanks: U.S. News 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 Ph.D. is a necessary escalation, another case of costly signaling to potential employers." 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." 
The Economist published an article in 2010 citing various criticisms against the state of Ph.D.s. These included a prediction by economist Richard B. Freeman that, based on pre-2000 data, only 20% of life science Ph.D. 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 Ph.D.s. 
The U.S. higher education systems often offers little incentive to move students through Ph.D. programs quickly, and may even provide incentive to slow them down. To counter this, 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 Ph.D. programs to be training for careers, outside academia, but still at high-level positions. This development can be seen in the extensive number of Ph.D. 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 Ph.D. 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.).  Other articles in Nature have also examined the issue of PhD reform.   
In German-speaking nations; most Eastern European nations; successor states of the former Soviet Union; most parts of Africa, Asia, and many Spanish-speaking countries, the corresponding degree to a Doctor of Philosophy is simply called "Doctor" ( Doktor ), and the subject area is distinguished by a Latin suffix (e.g., "Dr. med." for Doctor medicinae , Doctor of Medicine; "Dr. Rer. nat." for Doctor rerum naturalium , Doctor of the Natural Sciences; "Dr. Phil." for Doctor philosophiae , Doctor of Philosophy; " Dr. iur. " for Doctor iuris , Doctor of Laws). 
Degrees around the globe
The UNESCO, in its International Standard Classification of Education (ISCED), states that: "Programmes to be classified at ISCED level 8 are referred to in many ways around the world such as PhD, DPhil, D.Lit, D.Sc, LL.D, Doctorate or similar terms. However, it is important to note that programmes with a similar name to 'doctor' should only be included in ISCED level 8 if they satisfy the criteria described in Paragraph 263. For international comparability purposes, the term 'doctoral or equivalent' is used to label ISCED level 8". 
In Argentina, the admission to a Ph.D. program at public Argentine University requires the full completion of a Master's degree or a Licentiate degree. Non-Argentine Master's titles are generally accepted into a Ph.D. program when the degree comes from a recognized university.
While a significant portion of postgraduate students finances their tuition and living costs with teaching or research work at private and state-run institutions, international institutions, such as the Fulbright Program and the Organization of American States (OAS), have been known to grant full scholarships for tuition with apportions for housing. 
Requirements for completion
Upon completion of at least two years' research and coursework as a graduate student, a candidate must demonstrate truthful and original contributions to his or her specific field of knowledge within a frame of academic excellence.  The doctoral candidate's work should be presented in a dissertation or thesis prepared under the supervision of a tutor or director, and reviewed by a Doctoral Committee. This Committee should be composed of examiners that are external to the program, and at least one of them should also be external to the institution. The academic degree of Doctor, respective to the correspondent field of science that the candidate has contributed to original and rigorous research, is received after a successful defence of the candidate's dissertation. 
Admission to a Ph.D. program in Australia requires applicants to demonstrate the capacity to undertake research in the proposed field of study. The standard requirement is a bachelor's degree with either first-class or upper second-class honours. Research master's degrees and coursework master's degrees with a 25% research component are usually considered equivalent. It is also possible for research master's degree students to 'upgrade' to Ph.D. candidature after demonstrating sufficient progress.
Ph.D. students are sometimes offered a scholarship to study for their Ph.D. degree. The most common of these are the government-funded Australian Postgraduate Award (APA), which provides a living stipend to students of approximately A$25,800 a year (tax-free). APAs are paid for a duration of 3 years, while a 6-month extension is usually possible upon citing delays out of the control of the student.  Some universities also fund a similar scholarship that matches the APA amount. Due to a continual increase in living costs, many Ph.D. students are forced to live under the poverty line.  In addition to the more common APA and university scholarships, Australian students have other sources of scholarship funding.
Australian citizens, permanent residents, and New Zealand citizens are not charged course fees for their Ph.D. or research master's degree, with exception to the student services and amenities fee (SSAF) which is set by each university and typically involves the largest amount allowed by the Australian government. All fees are paid for by the Australian government, except for the SSAF, under the Research Training Scheme.  International students and coursework master's degree students must pay course fees unless they receive a scholarship to cover them.
Requirements for completion
Completion requirements vary. Most Australian Ph.D. programs do not have a required coursework component. The credit points attached to the degree are all in the product of the research, which is usually an 80,000-word thesis that makes a significant new contribution to the field. The Ph.D. thesis is sent to external examiners who are experts in the field of research and who have not been involved in the work. Examiners are nominated by the candidate's university and their identities are often not revealed to the candidate until the examination is complete. A formal oral defence is generally not part of the examination of the thesis, largely because of the distances that would need to be travelled by the overseas examiners. Recent pressure on the higher degree by research (HDR) students to publish has resulted in increasing interest in Ph.D by publication as opposed to the more traditional Ph.D dissertation .
Admission to a doctoral programme at a Canadian university usually requires completion of a Master's degree in a related field, with sufficiently high grades and proven research ability. In some cases, a student may progress directly from an Honours Bachelor's degree to a Ph.D. program; other programs allow a student to fast-track to a doctoral program after one year of outstanding work in a Master's program (without having to complete the Master's).
An application package typically includes a research proposal, letters of reference, transcripts, and in some cases, a writing sample or Graduate Record Examinations scores. A common criterion for prospective Ph.D. students is the comprehensive or qualifying examination, a process that often commences in the second year of a graduate program. Generally, successful completion of the qualifying exam permits continuance in the graduate program. Formats for this examination include oral examination by the student's faculty committee (or a separate qualifying committee), or written tests designed to demonstrate the student's knowledge in a specialized area (see below) or both.
At English-speaking universities, a student may also be required to demonstrate English language abilities, usually by achieving an acceptable score on a standard examination (for example the Test of English as a Foreign Language). Depending on the field, the student may also be required to demonstrate ability in one or more additional languages. A prospective student applying to French-speaking universities may also have to demonstrate some English language ability.
While some students work outside the university (or at student jobs within the university), in some programs students are advised (or must agree) not to devote more than ten hours per week to activities (e.g., employment) outside of their studies, particularly if they have been given funding. For large and prestigious scholarships, such as those from NSERC and Fonds québécois de la recherche sur la nature et les technologies, this is an absolute requirement.
At some Canadian universities, most Ph.D. students receive an award equivalent to part or all of the tuition amount for the first four years (this is sometimes called a tuition deferral or tuition waiver). Other sources of funding include teaching assistantships and research assistantships; experience as a teaching assistant is encouraged but not requisite in many programs. Some programs may require all Ph.D. candidates to teach, which may be done under the supervision of their supervisor or regular faculty. Besides these sources of funding, there are also various competitive scholarships, bursaries, and awards available, such as those offered by the federal government via NSERC, CIHR, or SSHRC.
Requirements for completion
In general, the first two years of study are devoted to completion of coursework and the comprehensive examinations. At this stage, the student is known as a "Ph.D. student" or "doctoral student". It is usually expected that the student will have completed most of his or her required coursework by the end of this stage. Furthermore, it is usually required that by the end of eighteen to thirty-six months after the first registration, the student will have successfully completed the comprehensive exams.
Upon successful completion of the comprehensive exams, the student becomes known as a "Ph.D. candidate". From this stage on, the bulk of the student's time will be devoted to his or her own research, culminating in the completion of a Ph.D. thesis or dissertation. The final requirement is an oral defence of the thesis, which is open to the public in some, but not all, universities. At most Canadian universities, the time needed to complete a Ph.D. degree typically ranges from four to six years. It is, however, not uncommon for students to be unable to complete all the requirements within six years, particularly given that funding packages often support students for only two to four years; many departments will allow program extensions at the discretion of the thesis supervisor and/or department chair. Alternate arrangements exist whereby a student is allowed to let their registration in the program lapse at the end of six years and re-register once the thesis is completed in draft form. The general rule is that graduate students are obligated to pay tuition until the initial thesis submission has been received by the thesis office. In other words, if a Ph.D. student defers or delays the initial submission of their thesis they remain obligated to pay fees until such time that the thesis has been received in good standing.
In Colombia, the Ph.D. course admission may require a master's degree (Magíster) in some universities, especially public universities. However, it could also be applied for a direct doctorate in specific cases, according to the jury's recommendations on the thesis proposal.
Most of the postgraduate students in Colombia must finance their tuition fees by means of teaching assistant seats or research works. Some institutions such as Colciencias, Colfuturo, and Icetex grant scholarships or provide awards in the form of forgivable loans. 
Requirements for completion
After two or two and a half years it is expected the research work of the doctoral candidate to be submitted in the form of oral qualification, where suggestions and corrections about the research hypothesis and methodology, as well as on the course of the research work are performed. The Ph.D. degree is only received after a successful defence of the candidate's thesis is performed (four or five years after the enrollment), and most of the times also requiring the most important results having been published in at least one peer-reviewed high impact international journal.
In Finland, the degree of filosofian tohtori (abbreviated FT ) is awarded by traditional universities, such as University of Helsinki. A Master's degree is required, and the doctorate combines approximately 4–5 years of research (amounting to 3–5 scientific articles, some of which must be first-author) and 60 ECTS points of studies.  Other universities such as Aalto University award degrees such as tekniikan tohtori ( TkT , engineering), taiteen tohtori ( TaT , art), etc., which are translated in English to Doctor of Science (D.Sc.), and they are formally equivalent. The licentiate ( filosofian lisensiaatti or FL ) requires only 2–3 years of research and is sometimes done before an FT.
Before 1984 three research doctorates existed in France: the State doctorate ( doctorat d'État , the old doctorate introduced in 1808), the third cycle doctorate ( doctorat de troisième cycle , created in 1954 and shorter than the State doctorate) and the diploma of doctor-engineer ( diplôme de docteur-ingénieur created in 1923), for technical research. After 1984, only one type of doctoral degree remained, called "doctorate" ( Doctorat ). The latter is equivalent to the Ph.D.
Students pursuing the Ph.D. degree must first complete a master's degree program, which takes two years after graduation with a bachelor's degree (five years in total). The candidate must find funding and a formal doctoral advisor (Directeur de thèse) with a habilitation throughout the doctoral program.
The Ph.D. admission is granted by a graduate school (in French, "école doctorale"). A Ph.D. candidate can follow some in-service training offered by the graduate school while continuing his or her research at the laboratory. His or her research may be carried out in a laboratory, at a university, or in a company. In the last case, the company hires the candidate and he or she is supervised by both the company's tutor and a labs' professor. The validation of the Ph.D. degree requires generally 3 to 4 years after the master's degree.
The financing of Ph.D. research comes mainly from funds for research of the French Ministry of Higher Education and Research. The most common procedure is a short-term employment contract called doctoral contract: the institution of higher education is the employer and the Ph.D. candidate the employee. However, the candidate can apply for funds from a company who can host him or her at its premises (as in the case where Ph.D. candidates do their research in a company). As another encountered situation, the company and the institute can sign together with a funding agreement so that the candidate still has a public doctoral contract, but is daily located in the company (for example, it is particularly the case of (French) Scientific Cooperation Foundation). Many other resources come from some regional/city projects, some associations, etc.
In India, generally, a master's degree is required to gain admission to a doctoral program. Direct admission to a Ph.D. programme after bachelors is also offered by the IIT s, the IIIT s, the NIT s and the Academy of Scientific and Innovative Research. In some subjects, doing a Masters in Philosophy (M.Phil.) is a prerequisite to starting a Ph.D. For funding/fellowship, it is required to qualify for the National Eligibility Test for Lectureship and Junior Research fellowship (NET for LS and JRF)  conducted by the federal research organisation Council of Scientific and Industrial Research (CSIR) and University Grants Commission (UGC).
In the last few years, there have been many changes in the rules relating to a Ph.D. in India. According to the new rules described by UGC, universities must have to conduct entrance exams in general ability and the selected subject. After clearing these tests, the shortlisted candidates need to appear for an interview with the available supervisor/guide. After successful completion of the coursework, the students are required to give presentations of the research proposal (plan of work or synopsis) at the beginning, submit progress reports, give a pre-submission presentation and finally defend the thesis in an open defence viva-voce.
In Germany, admission to a doctoral program is generally on the basis of having an advanced degree (i.e., a master's degree, diplom , magister, or staatsexamen ), mostly in a related field and having above-average grades. A candidate must also find a tenured professor from a university to serve as the formal advisor and supervisor ( Betreuer ) of the dissertation throughout the doctoral program called Promotion . This supervisor is informally referred to as Doktorvater or Doktormutter , which literally translate to "doctor's father" and "doctor's mother" respectively.
While most German doctorates are considered equivalent to the PhD, an exception is a medical doctorate, where "doctoral" dissertations are often written alongside undergraduate study. The European Research Council decided in 2010 that those doctorates do not meet the international standards of a PhD research degree.   There are different forms of the university-level institution in Germany, but only professors from "Universities" (Univ.-Prof.) can serve as doctoral supervisors – "Universities of Applied Sciences" (Fachhochschulen) are not entitled to award doctorates,  although some exceptions apply to this rule. 
Depending on the university, doctoral students ( Doktoranden ) can be required to attend formal classes or lectures, some of them also including exams or other scientific assignments, in order to get one or more certificates of qualification (Qualifikationsnachweise). Depending on the doctoral regulations (Promotionsordnung) of the university and sometimes on the status of the doctoral student, such certificates may not be required. Usually, former students, research assistants or lecturers from the same university, may be spared from attending extra classes. Instead, under the tutelage of a single professor or advisory committee, they are expected to conduct independent research. In addition to doctoral studies, many doctoral candidates work as teaching assistants, research assistants, or lecturers.
The usual duration of a doctoral program largely depends on the subject and area of research; but, often three to five years of full-time research work are required.
In 2014, the median age of new Ph.D. graduates was 30.4 years of age. 
USSR, Russian Federation and former Soviet Republics
The degree of Candidate of Sciences (Russian: кандидат наук, Kandidat Nauk) was the first advanced research qualification in the former USSR (it was introduced there in 1934) and some Eastern Bloc countries (Czechoslovakia, Hungary) and is still awarded in some post-Soviet states (Russian Federation, Belarus, and others). According to, in countries with a two-tier system of doctoral degrees (like Russian Federation, some post-Soviet states, Germany, Poland, Austria and Switzerland), should be considered for recognition at the level of the first doctoral degree, and in countries with only one doctoral degree, the degree of Kandidat Nauk should be considered for recognition as equivalent to this Ph.D. degree.
As most education systems only have one advanced research qualification granting doctoral degrees or equivalent qualifications (ISCED 2011,  par.270), the degree of Candidate of Sciences (Kandidat Nauk) of the former USSR counties is usually considered at the same level as the doctorate or Ph.D. degrees of those countries.  
According to the Joint Statement by the Permanent Conference of the Ministers for Education and Cultural Affairs of the Länder of the Federal Republic of Germany (Kultusministerkonferenz, KMK), German Rectors' Conference (HRK) and the Ministry of General and Professional Education of the Russian Federation, the degree of Kandidat Nauk is recognised in Germany at the level of the German degree of Doktor and the degree of Doktor Nauk at the level of German Habilitation.   The Russian degree of Kandidat Nauk is also officially recognised by the Government of the French Republic as equivalent to French doctorate.  
According to the, for purposes of international educational statistics, Kandidat Nauk (Candidate of Sciences) belongs to ISCED level 8, or "doctoral or equivalent", together with Ph.D., D.Phil., D.Litt., D.Sc., LL.D., Doctorate or similar. It is mentioned in the Russian version of ISCED 2011 (par.262) on the UNESCO website as an equivalent to Ph.D. belonging to this level.  In the same way as Ph.D. degrees awarded in many English-speaking countries, Kandidat Nauk (Candidate of Sciences) allows its holders to reach the level of the Docent.  The second doctorate  (or post-doctoral degree)   in some post-Soviet states called Doctor of Sciences (Russian: доктор наук, Doktor Nauk) is given as an example of second advanced research qualifications or higher doctorates in ISCED 2011  (par.270) and is similar to Habilitation in Germany, Poland and several other countries.   It constitutes a higher qualification compared to Ph.D. as against the or. 
About 88% of Russian students studying at state universities study at the expense of budget funds.  The average stipend in Russia (as of August 2011) is $430 a year ($35/month).  The average tuition fee in graduate school is $2,000 per year. 
The Dottorato di ricerca (research doctorate), abbreviated to "Dott. Ric." or "Ph.D.", is an academic title awarded at the end of a course of not less than three years, admission to which is based on entrance examinations and academic rankings in the Bachelor of Arts (" Laurea Triennale") and Master of Arts ("Laurea Magistrale" or "Laurea Specialistica"). While the standard Ph.D. follows the Bologna process, the M.D.-Ph.D. programme may be completed in two years.
The first institution in Italy to create a doctoral program (Ph.D.) was Scuola Normale Superiore di Pisa in 1927 under the historic name "Diploma di Perfezionamento" .   Further, the research doctorates or Ph.D. ( Dottorato di ricerca ) in Italy were introduced by law and Presidential Decree in 1980,   referring to the reform of academic teaching, training and experimentation in an organisation and teaching methods.  
Hence, the Superior Graduate Schools in Italy  ( Scuola Superiore Universitaria ),  also called Schools of Excellence ( Scuole di Eccellenza )   such as Scuola Normale Superiore di Pisa and Sant'Anna School of Advanced Studies still keep their reputed historical "Diploma di Perfezionamento" Ph.D. title by law   and MIUR Decree.  
Doctorate courses are open, without age or citizenship limits, to all those who already hold a " laurea magistrale " (master degree) or similar academic title awarded abroad which has been recognised as equivalent to an Italian degree by the Committee responsible for the entrance examinations.
The number of places on offer each year and details of the entrance examinations are set out in the examination announcement.
A doctoral degree (Pol. doktor ), abbreviated to Ph.D. (Pol. dr ) is an advanced academic degree awarded by universities in most fields      as well as by the Polish Academy of Sciences,  regulated by the Polish parliament acts  and the government orders, in particular by the Ministry of Science and Higher Education of the Republic of Poland. Commonly, students with a master's degree or equivalent are accepted to a doctoral entrance exam. The title of Ph.D. is awarded to a scientist who 1) completed a minimum of 3 years of Ph.D. studies (Pol. studia doktoranckie ; not required to obtain Ph.D.), 2) finished his/her theoretical and/or laboratory's scientific work, 3) passed all Ph.D. examinations, 4) submitted his/her dissertation, a document presenting the author's research and findings,  5) successfully defended his/her doctoral thesis. Typically, upon completion, the candidate undergoes an oral examination, always public, by his/her supervisory committee with expertise in the given discipline.
Starting in 2016,  in Ukraine Doctor of Philosophy (PhD, Ukrainian: Доктор філософії) is the highest education level and the first science degree. PhD is awarded in recognition of a substantial contribution to scientific knowledge, the origination of new directions and visions in science. A PhD degree is a prerequisite for heading a university department in Ukraine. Upon completion of a PhD, a PhD holder can elect to continue his studies and get a post-doctoral degree called "Doctor of Sciences" (DSc. Ukrainian: Доктор наук ), which is the second and the highest science degree in Ukraine.
The doctorate was introduced in Sweden in 1477 and in Denmark-Norway in 1479 and awarded in theology, law, and medicine, while the magister's degree was the highest degree at the Faculty of Philosophy, equivalent to the doctorate.
Scandinavian countries were among the early adopters of a degree known as a doctorate of philosophy, based upon the German model. Denmark and Norway both introduced the Dr. Phil(os). degree in 1824, replacing the Magister's degree as the highest degree, while Uppsala University of Sweden renamed its Magister's degree Filosofie Doktor (fil. dr) in 1863. These degrees, however, became comparable to the German Habilitation rather than the doctorate, as Scandinavian countries did not have a separate Habilitation. 
The degrees were uncommon and not a prerequisite for employment as a professor; rather, they were seen as distinctions similar to the British (higher) doctorates (D.Litt., D.Sc.). Denmark introduced an American-style Ph.D. in 1989; it formally replaced the Licentiate's degree and is considered a lower degree than the dr. phil. degree; officially, the PhD. is not considered a doctorate, but unofficially, it is referred to as "the smaller doctorate", as opposed to the dr. phil., "the grand doctorate". Holders of a PhD. degree are not entitled to style themselves as "Dr."  Currently Denmark distinctions between the dr. phil. as the proper doctorate and a higher degree than the PhD, whereas in Norway, the historically analogous dr. philos. the degree is officially regarded as equivalent to the new PhD.
In Sweden, the doctorate of philosophy was introduced at Uppsala University's Faculty of Philosophy in 1863. In Sweden, the Latin term is officially translated into Swedish filosofie doktor and commonly abbreviated fil. dr or FD. The degree represents the traditional Faculty of Philosophy and encompasses subjects from biology, physics, and chemistry, to languages, history, and social sciences, being the highest degree in these disciplines. Sweden currently has two research-level degrees, the Licentiate's degree, which is comparable to the Danish degree formerly known as the Licentiate's degree and now as the PhD, and the higher doctorate of philosophy, Filosofie Doktor . Some universities in Sweden also use the term teknologie doktor for doctorates awarded by institutes of technology (for doctorates in engineering or natural science related subjects such as materials science, molecular biology, computer science etc.). The Swedish term fil. dr is often also used as a translation of corresponding degrees from e.g. Denmark and Norway.
Doctoral degrees are regulated by Real Decreto (Royal Decree in Spanish) R.D. 99/2011 from the 2014/2015 academic year.  They are granted by a university on behalf of the King, and its diploma has the force of a public document. The Ministry of Science keeps a National Registry of Theses called TESEO. 
All doctoral programs are of a research nature. A minimum of three years of study are required, in one stage only:
- A 3-year (or longer) period of research. Extensions may be requested for maximum 5 years. The student must write his thesis presenting a new discovery or original contribution to science. If approved by her or his "thesis director (or directors)", the study will be presented to a panel of 5 distinguished scholars. Any doctor attending the public presentations is allowed to challenge the candidate with questions on his research. If approved, he will receive the doctorate. Four marks can be granted: Unsatisfactory, Pass, Satisfactory, and Excellent. "Cum laude" (with all honours, in Latin) denomination can be added to the Excellent ones if all five members of the tribunal agreed. 
A doctoral degree is required to apply for a long-term teaching position at a university.
The social standing of doctors in Spain is evidenced by the fact that only Ph.D. holders, Grandees and Dukes can take a seat and cover their heads in the presence of the King.  All Doctor Degree holders are reciprocally recognized as equivalent in Germany and Spain ("Bonn Agreement of November 14, 1994"). 
Universities admit applicants to Ph.D. programs on a case-by-case basis; depending on the university, admission is typically conditional on the prospective student having completed an undergraduate degree with at least upper second-class honours or a postgraduate master's degree but requirements can vary.
In the case of the University of Oxford, for example, "The one essential condition of being accepted … is evidence of previous academic excellence, and of future potential."  Some UK universities (e.g. Oxford) abbreviate their Doctor of Philosophy degree as "DPhil", while most use the abbreviation "PhD"; these are in all other respects equivalent. Commonly, students are first accepted onto an MPhil or MRes programme and may transfer to Ph.D. regulations upon satisfactory progress, this is sometimes referred to as APG (Advanced Postgraduate) status. This is typically done after one or two years and the research work done may count towards the Ph.D. degree. If a student fails to make satisfactory progress, he or she may be offered the opportunity to write up and submit for an MPhil degree as is the case at the King's College London and the University of Manchester. In many universities, the MPhil is also offered as a stand-alone research degree.
Ph.D. students from countries outside the EU/EFTA area are required to comply with the Academic Technology Approval Scheme (ATAS), which involves undergoing a security clearance process with the Foreign Office for certain courses in medicine, mathematics, engineering and material sciences.   This requirement was introduced in 2007 due to concerns about overseas terrorism and weapons proliferation. 
In the United Kingdom, funding for Ph.D. students is sometimes provided by government-funded Research Councils or the European Social Fund, usually in the form of a tax-free bursary which consists of tuition fees together with a stipend.  Tuition fees are charged at different rates for "Home/EU" and "Overseas" students, generally £3,000–£6,000 per year for the former and £9,000–14,500 for the latter (which includes EU citizens who have not been normally resident in the EEA for the last three years), although this can rise to over £16,000 at elite institutions. Higher fees are often charged for laboratory-based degrees.  
The stipend is around £13,000 per year for three years,  (sometimes higher by £2,000–3,000 in London), whether or not the degree continues for longer (within the usual four-year span). This implies that the fourth year of Ph.D. work is often unfunded. A very small number of scientific studentships are sometimes paid at a higher rate - for example, in London, Cancer Research UK, the ICR and the Wellcome Trust stipend rates start at around £19,000 and progress annually to around £23,000 a year; an amount that is tax and national insurance free. Research Council funding is sometimes ' earmarked' for a particular department or research group, who then allocate it to a chosen student, although in doing so they are generally expected to abide by the usual minimum entry requirements (typically a first degree with upper second class honours, although successful completion of a postgraduate master's degree is usually counted as raising the class of the first degree by one division for these purposes). The availability of funding in many disciplines (especially humanities, social studies and pure science subjects) means that in practice only those with the best research proposals, references and backgrounds are likely to be awarded a studentship. The ESRC (Economic and Social Science Research Council) explicitly state that a 2.1 minimum (or 2.2 plus additional master's degree) is required—no additional marks are given for students with a first class honour or a distinction at the masters level. Since 2002, there has been a move by research councils to fund interdisciplinary doctoral training centres which concentrate resources on fewer higher quality centres.
Many students who are not in receipt of external funding may choose to undertake the degree part-time, thus reducing the tuition fees, as well as creating free time in which to earn money for subsistence. Students may also take part in tutoring, work as research assistants, or (occasionally) deliver lectures, at a rate of typically £12-14 per hour, either to supplement existing low income or as a sole means of funding. 
There is usually a preliminary assessment to remain in the program and the thesis is submitted at the end of a three- to the four-year program. These periods are usually extended pro rata for part-time students. With special dispensation, the final date for the thesis can be extended for up to four additional years, for a total of seven, but this is rare.  For full-time Ph.D.s, a 4-year time limit has now been fixed and students must apply for an extension to submit a thesis past this point. Since the early 1990s, British funding councils have adopted a policy of penalising departments where large proportions of students fail to submit their theses in four years after achieving Ph.D.-student status (or pro rata equivalent) by reducing the number of funded places in subsequent years.  Inadvertently, this leads to significant pressure on the candidate to minimise the scope of projects with a view on thesis submission, regardless of quality, and discourage time spent on activities that would otherwise further the impact of the research on the community (e.g. publications in high impact journals, seminars, workshops). Furthermore, supervising staff are encouraged in their career progression to ensure that the Ph.D. students under their supervision finalise the projects in three rather than the four years that the program is permitted to cover. These issues contribute to an overall discrepancy between supervisors and Ph.D. candidates in the priority they assign to the quality and impact of the research contained in a Ph.D. project, the former favouring quick Ph.D. projects over several students and the latter favouring a larger scope for their own ambitious project, training, and impact.
There has recently been an increase in the number of Integrated Ph.D. programs available, such as at the University of Southampton. These courses include a Master of Research (MRes) in the first year, which consists of a taught component as well as laboratory rotation projects. The Ph.D. must then be completed within the next 3 years. As this includes the MRes all deadlines and timeframes are brought forward to encourage completion of both MRes and Ph.D. within 4 years from commencement. These programs are designed to provide students with a greater range of skills than a standard Ph.D., and for the university, they are a means of gaining an extra years' fees from public sources.
In the United Kingdom, Ph.D. degrees are distinct from other doctorates, most notably the higher doctorates such as D.Litt. (Doctor of Letters) or D.Sc. (Doctor of Science), which may be granted on the recommendation of a committee of examiners on the basis of a substantial portfolio of submitted (and usually published) research. However, some UK universities still maintain the option of submitting a thesis for the award of a higher doctorate.
Recent years have seen the introduction of professional doctorates (D.Prof or ProfD), which are the same level as Ph.D.s but more specific in their field.  These tend not to be solely academic but combine academic research, a taught component and a professional qualification. These are most notably in the fields of engineering (Eng.D.), education (Ed.D.), educational psychology (D.Ed.Psych), occupational psychology (D.Occ Psych.) clinical psychology (D.Clin.Psych.), health psychology (DHealthPsy), social work (DSW), nursing (DNP), public administration (DPA), business administration (DBA), and music (DMA). These typically have a more formal taught component consisting of smaller research projects, as well as a 40,000–60,000-word thesis component, which together are officially considered equivalent to a Ph.D. degree.
In the United States, the Ph.D. degree is the highest academic degree awarded by universities in most fields of study. There are 282 universities in the United States that award the Ph.D. degree, and those universities vary widely in their criteria for admission, as well as the rigour of their academic programs. 
Requirements. U.S. students typically undergo a series of three phases in the course of their work toward the Ph.D. degree. The first phase consists of coursework in the student's field of study and requires one to three years to complete. This often is followed by a preliminary, a comprehensive examination, or a series of cumulative examinations where the emphasis is on breadth rather than depth of knowledge. The student is often later required to pass oral and written examinations in the field of specialization within the discipline, and here, depth is emphasized. Some Ph.D. programs require the candidate to successfully complete requirements in pedagogy (taking courses on higher level teaching and teaching undergraduate courses) or applied science (e.g., clinical practice and predoctoral clinical internship in Ph.D. programs in clinical, counselling, or school psychology).
Another two to eight years are usually required for the composition of a substantial and original contribution to human knowledge in the form of a written dissertation, which in the social sciences and humanities typically ranges from 50 to 450 pages. In many cases, depending on the discipline, a dissertation consists of a comprehensive literature review, an outline of methodology, and several chapters of scientific, social, historical, philosophical, or literary analysis. Typically, upon completion, the candidate undergoes an oral examination, sometimes public, by his or her supervisory committee with expertise in the given discipline.
Typically, Ph.D. programs require applicants to have a bachelor's degree in a relevant field (and, in many cases in the humanities, a master's degree), reasonably high grades, several letters of recommendation, relevant academic coursework, a cogent statement of interest in the field of study, and satisfactory performance on a graduate-level exam specified by the respective program (e.g., GRE, GMAT).  
Depending on the specific field of study, completion of a Ph.D. program usually takes four to eight years of study after the Bachelor's Degree; those students who begin a Ph.D. program with a master's degree may complete their Ph.D. degree a year or two sooner.  As Ph.D. programs typically lack the formal structure of undergraduate education, there are significant individual differences in the time taken to complete the degree. Overall, 57% of students who begin a Ph.D. program in the US will complete their degree within ten years, approximately 30% will drop out or be dismissed, and the remaining 13% of students will continue on past ten years. 
The number of Ph.D. diplomas awarded by US universities has risen nearly every year since 1957, according to data compiled by the US National Science Foundation. In 1957, US universities awarded 8,611 Ph.D. diplomas; 20,403 in 1967; 31,716 in 1977; 32,365 in 1987; 42,538 in 1997; 48,133 in 2007,  and 55,006 in 2015. 
Funding. Ph.D. students at U.S. universities typically receive a tuition waiver and some form of annual stipend. Many U.S. Ph.D. students work as teaching assistants or research assistants. Graduate schools increasingly encourage their students to seek outside funding; many are supported by fellowships they obtain for themselves or by their advisers' research grants from government agencies such as the National Science Foundation and the National Institutes of Health. Many Ivy League and other well-endowed universities provide funding for the entire duration of the degree program (if it is short) or for most of it.
Models of supervision
At some universities, there may be training for those wishing to supervise Ph.D. studies. There is now a lot of literature published for academics who wish to do this, such as Delamont, Atkinson, and Parry (1997). Indeed, Dinham and Scott (2001) have argued that the worldwide growth in research students has been matched by an increase in a 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 that a Ph.D. candidate may gain if he or she publishes work, and note that Ph.D. students are more likely to do this with adequate encouragement from their supervisors.
Wisker (2005) has noticed how research into this field has distinguished between two models of supervision: The technical-rationality model of supervision, emphasising technique; The negotiated order model, being less mechanistic and emphasising fluid and dynamic change in the Ph.D. 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 Ph.D. supervision. Similar expectations are implied by the Quality Assurance Agency's Code for Supervision (Quality Assurance Agency, 1999; cited in Wilkinson, 2005).
International PhD equivalent degrees
- Afghanistan: ډاکټر
- Albania: Doktorature (Dr.)
- Algeria: Doctorat, دكتوراه
- Argentina: Doctorado (Dr.)
- Armenia: գիտությունների թեկնածու, դոցենտ
- Austria: Doktor (Dr., plural: DDr.)
- Azerbaijan: Doktorantura (Dr.)
- Bangladesh: Doctorate
- Belarus: кандидат наук
- Belgium (Dutch-speaking): Doctor
- Belgium (French-speaking): Doctorat
- Bosnia and Herzegovina: Doktor
- Brazil: Doutorado
- Bulgaria: Доктор
- Burma: ပါရဂူဘြဲ႕
- China: 博士 (Bo-shi)
- Chile: Doctorado
- Colombia: Doctorado
- Costa Rica: Ph.D. or Doctorado (Dr.)
- Croatia: Doktor
- Czech Republic: CSc. and DrSc. was used till 1998, since 1998 Ph.D. written as Ph.D. is used
- Denmark: Licentiate, Magister, Ph.D. (the doctorates are higher degrees)
- Dominican Republic: Doctorado
- Ecuador: Doctorado
- El Salvador: Doctorado
- Egypt: Doctorat, دكتوراه
- Estonia: Doktor (Dr)
- Ethiopia: ዶክተር, Doctor (Ph.D., Dr.)
- Finland: Filosofian tohtori and any degree of tohtori
- France: Doctorat
- Germany: Doktor
- Greece: Διδακτορικό
- Hong Kong: 博士 (Doctor)
- Hungary: Doktor (Dr.)
- India: Doctorate
- Indonesia: Doktor
- Iran: دکترا (Doctora)
- Iraq: دكتوراه (Duktorah)
- Ireland: an Doctúireacht
- Israel: דוקטורט ("doctorat")
- Italy: Dottorato di ricerca
- Japan: 博士 ( hakushi )
- Jordan: دكتوراه (Doctorah)
- Korea: 박사 ( baksa )
- Kuwait: دكتوراه (Dektoraah)
- Kurdistan: دكتوراه (Doctorah)
- Latin America: Doctorado / Doctorate
- Latvia: Zinātņu doktors
- Lebanon: دكتوراه (doktorah)
- Lithuania: Daktaras
- Macau: 博士 (Doutoramento)
- Macedonia: Докторат
- Malaysia: Doktor Falsafah
- Mauritius: Doctor of Philosophy (PhD)
- Mexico: Doctorado
- Mongolia: Эрдэмтэн
- Morocco: Doctorat
- Nepal: Doctor
- Netherlands: Doctor
- Nigeria: Doctor of Philosophy (Ph.D.)
- Norway: Magister, Licentiate, doctorates (traditionally considered higher degrees), Ph.D.
- Pakistan: Doctor
- Palestine: دكتوراه (doktorah)
- Paraguay: Ph.D. or Doctorado (Dr.)
- Peru: Doctorado
- Philippines: Doktor
- Poland: Doktor
- Portugal: pt:Doutoramento
- Romania: Doctorat
- Russia: кандидат наук (PhD junior grade), ru: доктор наук (PhD senior grade)
- Saudi Arabia دكتوراه
- Singapore: Doctor
- Serbia: Доктор
- Slovakia: CSc. was used during communism and some years in 90s, now Ph.D. written as Ph.D. is used; DrSc. is a higher degree.
- Slovenia: Doktor znanosti
- Spain: Doctorado
- Sweden: Filosofie doktor (fil.dr., FD)
- Switzerland: Doctorat (Dr)
- Syria: دكتوراه (doktorah)
- Taiwan： 博士
- Thailand: ดุษฎีบัณฑิต
- Tunisia: دكتوراه (doktorah)
- Turkey: Doktora
- United Arab Emirates: ar:دكتوراه (doktorah)
- United Kingdom: Doctor of Philosophy (PhD, doctor, the abbreviation DPhil is used only by the University of Oxford and the University of Sussex)
- United States: Doctor of Philosophy (PhD)
- Ukraine: uk: Доктор філософії (PhD)
- Uruguay: Doctorado
- Uzbekistan: Fan nomzodi (CSc.)
- Venezuela: Doctorado
- Vietnam: Tiến sĩ
- History of higher education in the United States#Graduate schools
- List of fields of doctoral studies in the United States
- PhD in management, a program designed for students interested in becoming university professors in the field of business
- D.P.S., Doctor of Professional Studies
- Piled Higher and Deeper, Life (or the lack thereof) in Academia , a comic strip by Jorge Cham
- Terminal degree, the highest degree awarded in a field, usually a PhD