One of the most influential trends in university teaching has been rubbished as "intellectually bankrupt" and damaging to students in a study for the Learning and Skills Development Agency.
The common practice of identifying students' "learning style" and tailoring teaching methods to their individual needs should be abandoned, according to researchers behind the first major study into the technique.
Frank Coffied, who led the as-yet-unpublished research, said tens of thousands of students were being diagnosed as "verbalisers", "visualisers" or "theorisers" and taught accordingly, using systems that were nearly all invalid and driven by commercial companies seeking profits.
"The use of learning styles in higher education has become widespread, it is in everyday use in the mistaken belief that it will improve students' results," Professor Coffied said. "And while there may well be a genuine interest in devising individualised learning plans, much of the growth is driven by commercial interests. People are making huge amounts of money from selling online tests, which in most cases are worthless."
The research examined 13 of the most popular methods of identifying learning styles from a possible 71. Only two - the Entwistle and the Vermunt models - were judged to have value. The rest should be abandoned, a report on the research says.
"A thriving commercial industry has been built to offer advice on learning styles, and much of it consists of inflated claims and sweeping conclusions that go beyond the knowledge base," it says.
Some of the more extreme learning-styles theories claim, for example, that marriage partners should have compatible learning styles or that people from socially disadvantaged groups tend to have similar learning styles.
The research found that the notion of "styles" implied a fixed preference that took no account of student experience or environmental influences.
The danger, the research concludes, is that higher education ends up with "content-free pedagogy" where process is celebrated at the expense of content. "For some senior managers, for inspectors, for government agencies, policy-makers and politicians, the appeal of learning styles may prove convenient because it shifts the responsibility for enhancing the quality of learning from management to individual teachers and learners," the report says.
One of the most difficult problems is the proliferation of tests, which is the result of "conceptual confusion and a serious failure of theoretical coherence", according to the report.
Professor Coffield's research found that the interest in post-16 learning styles was encouraged by government policy, which aimed to develop skills for lifelong learning. "There is a strong intuitive appeal to the notion that we all have different styles of learning," the report says. "Yet beneath the apparently unproblematic appeal lies a host of problems."