Students are, however, under growing pressure to take less time over their theses.
The research councils, which fund most PhD studentships, and the universities are anxious to demonstrate that they can deliver value for money from the public funds that support research students. That means that most PhDs should be completed within four years: three years of funded research, plus up to a year's "grace", albeit without funding, to finalise the thesis.
In the sciences, where students usually complete their research more quickly, postgraduates report pressure from their departments to complete within the three funded years.
In part, this reflects a change in the way a PhD is regarded by academia. Students are no longer expected to produce a life's work. Instead, a doctorate is the final stage in their academic training, and a foundation for later research.
The emphasis is now on quality rather than quantity. Research councils are encouraging students to select a project that is manageable within three years.Historians, for example, might choose to study a five-year period instead of a decade. Accordingly, universities are cutting the maximum length of a thesis from 120,000 words to 80,000 words - still the length of a substantial academic text.
Students are also coming to a PhD better prepared. Research councils now fund postgraduate studies on a "one plus three" basis. This allows students to take a preparatory degree, such as an MA, or the new, more training-oriented Master of research (MRes), but still collect a further three-year award for a doctorate.
Masters degrees, and the MRes in particular, cover research methods and include a substantial dissertation. The Government and the research councils see MRes programmes as a bridge between a first degree and a doctorate; in the arts and social sciences, this role is already filled by the MA.
The growing popularity of preparatory degrees is one of the reasons behind the decision this summer by the Humanities Research Board, the research arm of the British Academy, to introduce targets for PhD submissions.
The mechanism is similar to that operated since the Eighties by the Economic and Social Research Council. Using a combination of targets and sanctions, the ESRC improved its four-year submission rate from 37 per cent (for students completing in 1986) to 73 per cent in 1993. Universities that fail to meet the council's targets are barred from accepting students on an ESRC award.
The HRB will not be using sanctions but it, too, is aiming for a rate of 70 per cent. Presently, around 45 per cent of humanities researchers complete their PhDs within four years.
"The target of 70 per cent submission is intended as a signal to institutions that we are not satisfied with the present position," says Dr Michael Jubb, deputy secretary at the British Academy.
"It has deliberately been set as a target to be achieved when the first cohort of students who have begun their doctoral research under the new 1+3 arrangements will come into our four-year survey," he explains. "The great majority of those who took up three-year awards in 1994 had already gained some experience of postgraduate study, often with the support of an award from the academy."
Some postgraduates are concerned that reducing the time allowed for a PhD might lead to lower quality research. Also, students who fall behind because of inadequate training or supervision, or a lack of facilities, fear they might be penalised. One of the reasons behind the target systems is to ensure that universities give adequate support to their doctoral students. The HRB, in particular, is concerned to reassure its students that the new targets should actually be to their benefit.
The ability to produce a concise document to an agreed deadline, however, is in itself a valuable academic skill. Requirements differ between subjects, but in many areas of academic research, a piece of work might never be considered totally finished, so the value of an extra year's research might be marginal.
As Catherine Belsey, professor of English at Cardiff and a member of the HRB's postgraduate committee, says: "A humanities student in his, or her, twenties is not going to make epoch-making statements about the subject. In the humanities you build up to it ... you do a PhD not to change the world, but to demonstrate that you can sustain an argument for the length of a book."Reuse content