A quarter of people who undertake a PhD fail to achieve their goal within seven years. Liz Lightfoot finds that one reason is the wrong choice of topic; another is the false belief that a thesis has to be totally original

Taking a PhD is not for the faint-hearted. First, you have to choose the right topic. Then you hope you come up with some novel findings, all the while trusting that your supervisor will give you the support you need.

Being too quick to satisfy the research demands of a department or the interests of a supervisor are recipes for failure, according to the first conference on the PhD experience organised by students for students in Hull last month.

Research students need to be highly motivated and able to work independently, which is difficult if you have chosen the wrong topic, says Faith Chan, a research student and graduate teaching assistant in the geography department of the University of Leeds, who spoke at the conference.

He realised, 18 months down the line after completing the field work, that he was no longer particularly interested in the subject of his thesis. It was a hard truth to face for the former environmental monitoring technician from Hong Kong who is staking his future on a PhD from a good UK university.

"The more I worked, the less motivation there was to read and think," he says. "This was due to my lack of personal interest in the project, which did not match my career goals."

As he considered the options, he discovered that his was not an isolated case. The sharp increase in graduate teaching assistantships has tempted PhD students to compromise their interests to fit in with the teaching and research needs of hard-pressed university departments.

He turned for advice to his supervisors. "Unfortunately, they did not fully understand the extent of my problems and believed I could cope with the project," he says. "I was enjoying the teaching and continued for a while." Finally he found the courage to seek a new topic and broke the news to the department. "I was lucky that the department supported me," he says.

Now he is in the first year of research into managing water resources on the border between China and Hong Kong, his homeland. "Before I took the job as a research student with 50 per cent teaching I didn't really think what the PhD was about. It was more about coming to Britain because I had a passport and it would help my career prospects. I didn't have a clear idea what I wanted to research and it was easy to take the supervisor's idea.

"I should have seen it earlier, but I let it go and I spent 18 months wasting time and resources. Time is important and the resources of the university are important, but you need to understand yourself and your interests and make sure you share them with your supervisor. It's not a job; it is your ambition and your future."

Not all the personal stories at the conference were as searing as Faith Chan's. For Ros Aniza Mohd-Shariff-Tawil, an accountant from Malaysia, balancing research with the demands of three small children is a roller-coaster experience. But it can be done.

Wanting a new career as an academic, she enrolled for a PhD at the University of Durham, bringing her husband and three children under six with her. "Research is intensely emotional, sometimes lonely, sometimes frightening but ultimately exhilirating, like climbing a mountain and finding clarity at the top," she says. "In the week I work and at the weekend we do sightseeing, trips or car boot sales as a family."

Another cause of PhD failure is the false belief that a doctoral thesis has to be totally original, the conference heard. A quarter of all PhD students fail to qualify within seven years. There are three main reasons for this: they are too ambitious; they choose the wrong topic; or the relationship between student and supervisor breaks down.

These problems are all part of the experience for nearly 100,000 students undertaking doctoral research at UK universities, but the suggestion that their work does not need to be original stunned the delegates in Hull. "In that case, what is the difference between an MA and a PhD?" asked one.

According to Dr Kevin Morrell, senior lecturer in human resource management at the University of Birmingham, it is very hard to find something new and original when tens of thousands of others have been working in a field before you. "You don't have to come up with something earth-shattering and new," he says. "People think they have to do something that will make the community look at the world in a different way, but it's easy to overestimate what 'new' means. But relax, you don't have to."

What you need to do is to make a contribution to knowledge and understanding, he advises.

Research students used to produce hundreds of thousands of words but today, certainly in the social sciences and arts, the PhD is limited to 80,000 words, according to Caroline Kennedy-Pipe, Hull's professor of war studies. The originality clause has been removed. "Students are now required to make significant contributions to knowledge rather than create something wholly original," she says. "This makes the process more defined and measured in many institutions."

None of this amounts to dumbing down. "The new PhD thesis may appear less substantive, but it is actually more concise and professional," she says.

Although students don't need to worry about being original, they do need to bother about planning their time, according to Professor David Drewry, the vice-chancellor of Hull University. "Don't get on a travellator and find it is taking you somewhere you don't want to go," he says. "The speed and direction are important. You have to have fire in your belly because after year two, when things aren't going right, the only thing that will keep you going is that you love it."

It's a lesson that Theresa Mercer, one of the Hull organisers, learned the hard way. She accepted a PhD place at Imperial and moved her things to London from her home in Hull. "When I started I found my role was quite different to what I'd thought it would be. I couldn't change because I was part of a team and I didn't want to let the team down," she says. Two weeks in she packed up and returned to Hull where she is doing a PhD, funded by the Engineering and Physical Sciences Research Council, into the environmental impact of a common wood preservative.

It's tempting to accept a position with a prestigious university without paying attention to the requirements of the research brief, says Andrew Kythreotis, the conference co-organiser. He turned down a PhD studentship place in the renowned geography department at Durham because he didn't think he would have complete ownership of a PhD with a prescribed topic that was funded by the Economic and Social Research Council. He then found a position as a teaching assistant at Hull to support a PhD on the relationship between voluntary groups and the Government in promoting sustainability.

A breakdown in the relationship with a supervisor, can arise from a misunderstanding of the part each should play, according Morrell. "It sounds laughable, but you must manage your supervisor and have regular meetings."

What about the burning desire to do the research? That may be helpful, but it may also be dangerous, he says. "Choose a question that would be reasonable to ask and answer in the time. Keep your eye on the ultimate goal because you can't cash in the PhD chip unless you finish the work."

And the lecturer's final piece of advice? Students who need reassurance should read other PhDs in the field. "You will find the quality varies considerably, but they all got the same qualification."

Tips for managing your supervisor

DO keep your promises

DO make specific commitments and ensure that you honour them

DO be keen and open to their suggestions and criticism

DO plan regular meetings

DO clarify expectations

DO be honest about how things are going

DO produce quality written work, not a sloppy first draft

DON'T disappear without warning

DON'T visit for no reason

DON'T phone to have a casual chat that doesn't relate to your research

DON'T treat meetings as a contest

DON'T be overly defensive

DON'T fail to read what they have suggested you read

DON'T miss your deadlines

DON'T fail to hand in your work