A leading educationalist in the UK says that kids learn four times fast when they are taught by the best teachers, compared to those taught by the worst ones.
Professor Dylan Wiliam, of the Institute of Education, London, suggests that the Government better focus on making teachers better at their jobs, instead of cutting class sizes or buying new technology.
"Children in the most effective classrooms will learn in six months what students in an average classroom learn in a year - and students in the least effective classrooms will take two years to learn it," the Telegraph quoted Prof. Wiliam as saying during a speech a conference in Cambridge on Thursday.
According to him, teaching teachers to use regular feedback on pupils' performances, known as "formative assessment", to aid learning is the best way to improve their performance.
"Simply telling teachers what to do doesn't work. It is impossible to prepare teachers for every situation they will face in the classroom," he said.
"A focus on formative assessment can generate as much as eight extra months of learning per year at a cost of only 2,000 pounds per classroom. This is around 20 times as cost-effective as class-size reduction," he added.