This article was written by Steve Higgins.

Filling classrooms to the brim with computers and tablets won’t necessarily help children get better grades. That’s the finding of a new report from the Organisation for Economic Co-operation and Development (OECD).

The report reviews the links between test results of 15-year-olds from 64 countries who took part in the OECD’s 2012 Programme for International Student Assessment (PISA) and how much the pupils used technology at home and school.

Pupils in 31 countries, not including the UK, also took part in extra online tests of digital reading, navigation and mathematics. The countries and cities that came top in these online tests were Singapore, South Korea, Hong Kong and Japan – who also perform well in paper-based tests. But pupils in these countries don’t necessarily spend a lot of time on computers in class.

The report also shows that in 2012, 96% of 15-year-old students in the 64 countries in the study reported that they have a computer at home, but only 72% reported that they used a desktop, laptop or tablet computer at school.

The OECD found that it was not the amount of digital technology used in schools that was linked with scores in the PISA tests, but what teachers ask pupils do with computers or tablets that counts. There is also an increasing digital divide between school and home.

These findings, as well previous evaluations, indicate that just increasing the provision and use of computers or other digital tools for students, either at home or at school, is unlikely to result in significant improvements in educational outcomes.

In fact, the study shows countries which have invested more in introducing computers in schools, such as Russia and Portugal, have improved slower, on average, than countries which have invested less. Results are similar across reading, mathematics and science.

Across the countries in the report, students who do not use computers in mathematics lessons (or use them only rarely) do better on paper-based tests than students who do use computers, after accounting for differences in socio-economic status.

However, there are some countries that buck this trend: in Belgium, Denmark and Norway there is a positive association between computer use in mathematics lessons and student performance in maths tests.

My interpretation here is that you have to know how to use technology well to get the best from it in an educational setting. Introducing technology may actually make the process of educational improvement more difficult as teachers have to adjust to technological change while trying to improve their wider teaching skills.

The Goldilocks principle

There is also a persuasive case that the effective use of digital technologies for learning is an example of the “Goldilocks Principle”. Too much is not a good thing, but nor is too little: you’ve got to get it just right.

The best performing countries don’t have students using technology a lot (it is hard to tell how much teachers use technology such as interactive whiteboards from the surveys), but some of the least successful are also the lowest users. Overall levels of computer use in schools above the current OECD average of about 25 minutes per day are associated with significantly poorer results. To get the best from technology, it appears that you should be neither too hot, nor too cold.

However, this principle also applies to students’ use at home too, where the best performing students don’t use technology excessively, but they do have access to it. It would be wrong to assume a causal link here. It seems more likely that motivated and hard-working students get on with their schoolwork or do other things at home.

The principle is also evident in different subjects of the curriculum. As the graph below shows, the report suggests that students who make slightly below-average use of computers at school actually have the highest performance in digital reading. It is also important to note that for wider reading skills, rare users actually perform better than intensive users. In terms of the development of reading skills, digital technology may act as a distraction.

What teachers change

One point briefly mentioned in the OECD report, but worth developing further, is the opportunity cost of technology use. What do teachers stop doing when they use computers or get their students to, and what do 15-year-olds not do at home when they use technology?

The net educational benefit of digital technology use in classrooms is likely to depend on whether such technology displaces other less effective learning activities or increases the efficiency of time that is spent learning. It is hard to assess this, but we should explore more carefully what technology replaces and whether it really is better than what went before.

There is no simple message about technology use in schools from this OECD report – and one of its main conclusions is unsurprising: “In the end, technology can amplify great teaching, but great technology cannot replace poor teaching.”

Obvious though this point may seem, I am sceptical that this will convince those in charge of the education purse strings to invest the same sums they have been prepared to spend on the purchase of technology equipment, on the effective training and development of teachers to use it well in their lessons. This is despite the fact that we know it is the quality of our teachers which determines the quality of the education in our schools.

Steve Higgins, Professor of Education, Durham University

This article was originally published on The Conversation. Read the original article.