“It doesn’t matter if the cat is black or white as long as it catches mice.” These words, uttered by Deng Xiaoping, express the essence of pragmatism. Tony Blair was less poetic, but equally to the point: “what’s right is what works.”

This doesn’t leave much room for principle, let alone ideology; but in those areas where it’s possible to make an objective assessment of the effectiveness of different policies, there seems little justification for not doing what works.

Education is a good example. We now have a whole heap of evidence for what works in the classroom and, just as importantly, what doesn’t.

In a new report for the Sutton Trust, Professor Robert Coe and his colleagues provide an excellent summary of the current state of play. They also turn a spotlight on the unfounded assumptions that continue to exert an influence in our schools:

“…many common practices can be harmful to learning and have no grounding in research. Examples include using praise lavishly, allowing learners to discover key ideas by themselves, grouping students by ability and presenting information to students based on their ‘preferred learning style’.

“On the other hand, some other teaching approaches are supported by good evidence of their effectiveness. Many of these are obvious and widely practiced, but others are at odds with common assumptions.”

Some ideological approaches to education receive more support from the evidence-base than others. For instance, those of traditionalist frame of mind will be pleased to see the cult of self-esteem exposed for what it is:

“For low-attaining students praise that is meant to be encouraging and protective can actually convey a message of low expectations. The evidence shows children whose failure generates sympathy are more likely to attribute it to lack of ability than those who are presented with anger…

“Attempts to enhance motivation prior to teaching content are unlikely to succeed and even if they do the impact on subsequent learning is close to zero. If the poor motivation of low attainers is a logical response to repeated failure, starting to get them to succeed through learning content will improve motivation and confidence.”

Traditionalists will be less happy with what the report has to say on grouping pupils by ability – i.e. setting, streaming and (by extension) selection:

“Evidence on the effects of grouping by ability, either by allocating students to different classes, or to within-class groups, suggests that it makes very little difference to learning outcomes. It can result in teachers failing to accommodate different needs within an ability group and over-playing differences between groups, going too fast with the high-ability groups and too slow with the low.”

To be honest, this isn’t the result that many of us on the centre-right would expect or hope for. Yet we need to engage with the evidence in good faith. Instead of simply dismissing the findings that contradict our worldview, we should seek deeper explanations and endeavour to develop our understanding of the issues at stake. For instance, in regard to grouping by ability, we don’t have to deny the obvious (i.e. that children aren’t all equally able), but we should recognise that setting is a crude response to this reality.

On the whole, the evidence on what works in education is overwhelmingly in our favour. It confirms the importance of fundamentals like disciple, rigour and knowledge, not to mention teacher quality and home environment.

But where the truth is less convenient, it is far better to work through the implications than to hide behind our ideological barricades.