Millions of pounds may have been wasted on interactive whiteboards because too little research was carried out into their effects on teaching and learning, academics have warned.
The Government announced funding of pound;25 million this year for the teaching aids, even though other technologies could be more effective, a seminar at London university's institute of education was told.
Interactive whiteboards cost schools up to pound;8,000 in the first year, equivalent to 15 laptop computers for one class, said academics.
They said some schools have been so keen to embrace the new technology that they have removed all their conventional whiteboards. As a result, they have been left with nothing to write on when the hi-tech whiteboards malfunction or when projector bulbs burn out.
Adrian Mee, lecturer in education at the institute, said: "The Government decided to put pound;25m of solution into schools, then looked for a problem to fit it - I am not sure it should be that way round.
"Schools are quite often in a position where someone turns up with a cheque and says, 'Buy interactive whiteboards.'
"We are looking at a significant investment without much return. People should be able to choose the technology they want."
Laptops or tablet PCs and projectors are among the technologies that may be cheaper and more effective. Staff at the IoE admitted they have had similar problems. Once, they installed two interactive whiteboards opposite each other in one room, making it impossible to see both.
The Department for Education and Skills defended its investment in the technology and said evidence is emerging that learning has improved as a result.
A DfES spokesman said: "Education ministers are rightly enthusiastic about the impact that new technologies can make on raising attainment. The electronic interactive whiteboard is a very good example of a rapid advance in classroom ICT that is proving popular and effective.
"The vision is certainly that all classrooms will eventually be equipped with interactive whiteboards or their future equivalent."
The spokesman pointed to an Office for Standards in Education report on ICT in schools as evidence that whiteboards were a success and said that Newcastle university was also carrying out an evaluation.
Ofsted found that the technology improves the pace of lessons, as well as engaging lower-attaining pupils and encouraging better concentration.
But the report also said: "In only a small proportion of schools are whiteboards being used to full effect. In many schools, too few staff have had sufficient training to gain confidence in their use or to take any imaginative steps in using the new technology to meet the special needs of their pupils."
This report and the Newcastle study were begun after the decision to invest in whiteboards had been taken.