It is one of British higher education's great shibboleths: in order to be a good teacher, an academic must be doing research in the field in which he or she teaches.
The rationale is that research keeps teaching relevant and fresh. Students, according to the received wisdom, benefit by being taught by people who are at the cutting edge of their subject and whose enthusiasm for the subject is evinced by the very fact that they are research active. On the face of it, what student paying £3,000 a year for a degree would not want to be taught by such people?
Academics, not unreasonably, according to the argument, benefit by being allowed to continue the pursuit of knowledge that first attracted them to academe. Universities, in turn, benefit from academics' greater engagement and commitment to their subject, their department and, ultimately, their institution.
For years, an academic was a lecturer who conducted research. Those academics who were categorised as "teaching and research" comprised the single biggest academic grouping.
They still do. Just over half (51 per cent) of UK academics did both teaching and research in 2005-06, according to an analysis of data from the Higher Education Statistics Agency.
But the figure belies considerable change in the composition and the nature of higher education in Britain in the early 21st century.
Just three years earlier, in 2003-04, those classed as teaching and research accounted for 55 per cent of the academy.
Over the same period, the proportion of research-only staff also dropped, from 25 per cent of all academics in 2003-04 to 23 per cent in 2005-06. At the same time, the proportion of staff classed as teaching-only rose from 20 per cent to 26 per cent of all academics. And, perhaps most telling of all, the actual number of teaching-only academics increased by 37.87 per cent, compared with rises of 2.85 per cent and 3.08 per cent for teaching and research and research-only respectively.
If these trends continue, teaching-only staff could comprise the single largest grouping in academe within a decade.
Liz Beaty, director of learning and teaching at the Higher Education Funding Council for England, says: "I can see a situation where academics whose main focus is teaching come to dominate. In some institutions it is already true - although academics wouldn't describe themselves as teaching-only because they are active in scholarly work and active in publishing."
For Malcolm Keight, head of higher education at the University and College Union, that prospect is alarming.
"I certainly hope they never become a majority," he says. "That would bring into question the nature of higher education. We may have institutions where less research is undertaken, but I can't see how we would sustain higher education without the essential link between teaching and research."
Many academics share Keight's view, but the changes seem to be well under way. To try to understand their likely impact, one must consider what is driving them.
There are three main reasons: the research assessment exercise, the rise of the student as a fee-paying consumer and widespread contractual rationalisations across universities over the past few years. (It should also be noted that the inclusion in the figures produced by Hesa from 2002 of hourly paid staff - who are almost exclusively teaching-only - accounted for some of the earlier rise.)
A major influence is the RAE. In its 22 years, the RAE served a useful role in channelling money to some of the UK's best academics and departments. But the system created losers as well as winners.
Some 40 per cent of academics were not submitted to the 2001 RAE. For many academics, this amounted to being given research-inactive status.
Research selectivity focused the minds of university managers who reassessed their institutions' academic resources. For many the logic was simple: if an academic's research is not good enough for the RAE, why should the university waste precious resources supporting that research? How much more effective might it be to harness their talents to teaching and give the research money to someone who will make better use of it, the thinking goes.
David James, director of medical education at the University of Nottingham, says universities must be pragmatic when it comes to making the most of academics' talents.
"Maybe a person used to be a good researcher, but now he or she is burnt out and has had enough. Or perhaps that academic was good as a researcher for a particular subject, but changing fashions have meant that that research is not popular any more.
"All academics should go through an appraisal. Appraisals should judge their research, their teaching and their 'outside activities' such as participation in university committees. If they do not fulfil the criteria, most universities have processes that require the individual to change or go through a process of redundancy in the worst-case scenario," says James.
Beaty tends to agree but foresees big problems with a forced switch to teaching-only. "Universities can't afford to pay staff who are unproductive. But that is a long way from saying people should be forced back to teaching against their will. Students would only be disadvantaged if they found themselves being taught by someone who didn't like teaching and didn't care about student development."
Managers who wanted to justify such changes were handed a gift in 1998 when tuition fees for UK undergraduates were introduced. Teaching, which had played second fiddle to research, became a more important activity for universities, and having academics dedicated to the task made sense.
Many universities have applied this logic when structuring academics' contracts.
City University London has recorded the biggest rise in the number of teaching-only contracts, according to Hesa figures. The number of teaching-only contracts shot up from five in 2003 to 850 in 2006 at City. The university says an intake of visiting professors accounted for some of the increase.
At Newcastle University, the number of teaching-only contracts climbed by 133 per cent in the same period, from 60 to 140. "Some people are on teaching-only contracts because they have got to the point where their research career is not blossoming," says Kathy Wiles, head of quality, learning and teaching at Newcastle.
Similar rises in the number of teaching-only contracts were recorded at the universities of Birmingham, Southampton and Glasgow.
"This investment in staff whose role is to focus on driving forward innovation in teaching to enhance student learning has been a deliberate strategy," says a spokesperson for the University of Glasgow.
A University of Birmingham spokesperson says: "In so far as there has been a growth in the number of teaching-only staff, this has been driven by the need of the university to provide high-quality support for the learning and teaching needs of its students.
"We expect that our learning and teaching provision will continue to be met principally by staff who engage in both teaching and research, though we accept that there is a place within a research-led institution for a limited cadre of staff who specialise in teaching, learner support, innovation in teaching methodologies and in emerging educational technologies."
The need to maintain and enhance student satisfaction with quality teaching was underlined when the National Student Survey was introduced in 2005. The exercise allows students to name universities and departments whose teaching falls short of their expectations.
Leading research-led universities were once felt to be largely immune to criticism of their teaching quality, thanks in large part to the tenacity of the "good research means good teaching" theory. But those institutions found themselves under fire amid claims that that they were using postdoctoral students to run tutorials because the academics were too busy doing research.
There was also disturbing evidence that higher education was losing talented teaching staff who had become fed up with the lack of respect, the absence of career progression and inadequate reward.
Sixty per cent of institutions have had difficulty recruiting lecturers in recent years, particularly in IT, computing, business, science, engineering and medicine, according to the Government's 2003 White Paper, The Future of Higher Education.
Some of this attrition, mainly to the private sector, was down to market forces outside the control of higher education. But the White Paper acknowledged that too much emphasis had been put into encouraging universities to acquire their income through research projects. It promised extra funding for teaching and called for national standards for teaching and for the establishment of centres of excellence to reward and promote best teaching practice.
"Teaching has for too long been the poor relation in higher education," the paper says. "It has been seen by some institutions as an extra source of income to support the main business of research. This is a situation that cannot continue. Institutions must properly reward their best teaching staff, and all those who teach must take their responsibility seriously.
"It is not necessary to be active in cutting-edge research to be an excellent teacher."
A 2007 report for the Higher Education Academy, Linking Teaching and Research in Disciplines and Departments, tends to support this view. In it, the authors, Alan Jenkins, Mick Healey and Roger Zetter, report that interviews showed that Australian students valued research-active staff because their courses were thought to be up to date and staff were more interested in what they were teaching.
But the authors also say that their survey of UK students suggests that research-active staff were remote and that their research was quite different from the course material being taught. The report says: "The evidence shows little direct relationship between an individual's teaching effectiveness and research productivity, although recent work has shown the importance of mediating factors."
Last year, Leslie Wagner, the former chair of the HEA, announced that "formal criteria" would be formulated by the academy to make sure that teaching-only academics had a clear path of promotion in all British universities. Although some universities had already had measures in place to promote teaching-only academics, their efforts had been "fitful", Wagner remarked.
The conjunction of these factors is helping rehabilitate the image of the teaching-only academic. Crucially, the status of teaching-only academics is rising as universities adapt to the realities of a higher education market filled with students behaving like customers.
Beaty says: "The status of teaching-only academics is rising on the back of acknowledged professional standards for teaching and an increasing number of promotion prospects. These changes are not just lip service, they genuinely work."
Many institutions are already well ahead of the curve, having introduced pay and promotion schemes that put teaching-only staff on a par with their research-active peers. These may seem small steps, but for higher education they represent huge change.
Researchers at the University of Nottingham have found evidence of progress. They surveyed medical schools in 2003 to discover how teaching-only academics fared. They found that only ten out of 31 medical schools had reformed their promotional criteria to reward good teachers. A follow-up survey in 2006 found that the number of universities willing to put teaching-only staff on the same promotion system as research-led academics had doubled to 20.
"There was evidence of flexible promotion to professorial level at nine leading universities - Cardiff, Keele, King's College, Newcastle, Southampton, Sussex, University College, Warwick and York," says James, who helped to conduct the survey of 33 of Britain's top medical schools.
"There was a defined teaching route to chair at the universities of Birmingham, Dundee, Glasgow, Leeds, Nottingham and Sheffield. There were also three universities with flexible schemes: St George's, Imperial and Queen Mary," James notes.
"We'd been doing informal student surveys since 2001," says Ian Giles, director of education at the University of Southampton. "It was clear from our surveys that the students valued good teaching. We made it a clear priority to make sure they got it."
Southampton had good lecturers. The trick was to keep hold of them - and to attract more of the best from elsewhere. In 2002, the university succeeded in doing that by adopting a single pay scale for both teaching-only academics and research-led academics.
Under the scheme, teaching-only academics follow the same career steps and rates of pay as research-led academics, starting at teaching fellow, graduating to senior teaching fellow and finally to director of education, of which the university now has seven.
Last summer, the University of Bristol became the latest in a line of universities to put teaching-only academics on the same pay and promotion scale as research-led academics.
"A subculture had been created where if you wanted to get on in your career, you concentrated on research, not teaching," says David Clarke, Bristol's pro vice-chancellor. "We wanted to award clear status to the best teaching academics."
City University London was another university to respond quickly to student demands for good teaching. "City has one of the lowest proportions of Hefce funding of any university," says David Bolton, pro vice-chancellor for teaching and learning. "We rely heavily on student fee income, and our focus is clearly on the students who are paying us to teach them."
But some see the rise of teaching-only academics supported by new career paths and pay enhancements as a threat to the fabric of academic life. Critics argue that research-led teaching is essential if British universities are to protect their reputations for original thinking and research.
"Our vice-chancellor at Nottingham says he wants no more than 7.5 per cent of staff to be on teaching-only contracts," James says. "He says he wants the university to stay research-driven."
"Those on teaching-only contracts tend to be those who are at the end of their professional career. The usual scenario is that you will be told that you are not research-active enough. That means that your department doesn't have to list you as a researcher during the RAE submissions - and you get to avoid redundancy. It doesn't mean that you are a good teacher," he says.
At Newcastle, Wiles also reports some concerns. "Some of our research-led academics have had reservations about money and attention being diverted from research into teaching," she says. "They were worried that the importance of research would be watered down if we changed the system of promotion. But we want equity for people who bring talent to the table."
At the University of Sussex, Joanna Wright, the pro vice-chancellor, confirms that the university has 645 staff on teaching-only contracts, compared with 510 on teaching and research contracts and 300 research-only staff. But she says that most of those on teaching-only contracts are "people such as language instructors rather than core academics".
"We believe very firmly that good teaching needs to be linked with pioneering disciplinary and interdisciplinary research," Wright says.
At many institutions, teaching-only staff may be paid the same as their research-active peers and have the same career options, but there is clearly a way to go before teaching-only staff achieve true parity of esteem.
Given the continuing financial and reputational premium that attaches to research excellence, many universities will eschew any moves to significantly increase the number of teaching-only staff.
This raises the likelihood of two distinct types of academe sitting at either end of a UK higher education spectrum. At one end would be research institutes catering largely for postgraduate students supervised by research-active academics, and at the other, teaching-led institutions where undergraduates are taught by academics who do little or no research.
It is not an unusual model. The Chinese are focusing on cutting-edge research in ten world-class universities only. A similar story can be found in India, where most of the research-intensive study of science is done at the brand-new Institute of Technology at just seven sites across the country.
The question for policymakers and university leaders is whether the teaching-only academic is a sustainable model.
Teaching-only academics will necessarily have to keep abreast of the latest developments in their subjects. So, in this sense, although a teaching-only position excludes research on university time it does not preclude scholarship. But is scholarship, primarily the reading of relevant journals and papers, sufficient to engage academics in the way that research does? And could university managers monitor scholarship in the same way they can assess research output?
Some observers think these issues are outmoded. In their report, Jenkins, Healey and Zetter call on higher education to move beyond "the tired old teaching versus research debate".
What universities appear to be doing is circumventing that debate altogether. And, if the rise in teaching-only numbers is anything to go by, institutions are instead creating a reality where it is teaching or research. Most academics continue to do both, but for how long?
The sector's attempts to create remunerative parity between teaching-only and research-active academics are to be welcomed when both contribute to the success of their institutions.
Yet beyond this, the rise of teaching-only staff in higher education challenges the very concept of what it means to be an academic.
Perhaps the question for future generations of academics will be, "What kind of academic do I want to be?"
Stephen MacQueen is a beneficiary of the University of Bristol's new promotion system for teaching-only staff. And yet he has mixed feelings about the system.
MacQueen, who runs the avionic systems undergraduate degree programme at Bristol, is on the new Pathway Three promotion system designed to put "teaching-only" staff on the same career path as research-led academics.
"I've been working as a lecturer in this department for 16 years, and it has taken Bristol that long to promote me to the equivalent of senior lecturer," MacQueen observes.
Despite his promotion, MacQueen feels that he has been penalised by the university for choosing to pursue a teaching-only career. He may have been awarded a senior position, he says, but as a teaching-only lecturer, there is a glass ceiling.
"I don't believe that I can be promoted to professorial level," he says.
"It was only in August this year - ten years after being promoted to the role of 'lecturer' - that I got promoted to the equivalent level of 'senior lecturer', although my title is still 'avionic systems experimental officer'. Under the new system I am no longer known as an 'other related staff'. Instead, my title is senior teaching fellow.
"Looking back, I can see that I've been penalised for being teaching-only staff. I've taken on the teaching and administration duties of research-based academics, leaving them free to focus on their research and get fast-track promotions. But to be fair to the university, the reforms have tried to address this.
"The fixed promotion scheme is a definite improvement. Under the new scheme, staff on teaching-only contracts will have an automatic promotion from 'lecturer' to 'senior lecturer' after eight years - the same as academics on teaching-research contracts.
"The only thing is that there is nowhere to go from here," MacQueen says.
"I just want to get on with turning out good engineering students, and the fact that I'm not doing research enables me to make the students my top priority."
Bucks New University is an unashamedly teaching-oriented institution.
"Our students thrive because we concentrate all our efforts on them," explains Ray Batchelor, who teaches art and design at the university.
"The lecturers don't have a hankering to do research. You only want to work here if you really enjoy teaching. Lecturers are encouraged to do research - but in their own time."
This may be anathema to many academics, but Bucks New University is pioneering innovative teaching practices, new courses are being introduced and its campus is in a state of upheaval as workers in hard hats erect state-of-the-art teaching facilities.
"The aim is not to compete with the University of Oxford or Imperial College London," says David Gay, deputy director at Bucks New University. "Our aim is to give people second chances in life and to extend the range of people who want to learn and succeed. We don't give up on anybody.
"We have made it our job to be most welcoming and open to students from non-traditional backgrounds - and we were doing it long before the Government decided to make it a priority."
The university's effort and dedication are appreciated by its students. Marks in the National Student Survey assessing the quality of teaching at Bucks range between 61 per cent (biology and computer science) to 80 per cent for law.
But the news is not all positive. Students' "general level of satisfaction" with the university dropped from 73 per cent in 2006 to 68 per cent in 2007.