What goes on in your brain when you read this? Do you classify the ideas in it? Do you redefine problems it raises, check for bias, predict its conclusion? Maybe you weigh up the pros and cons of reading it to the end?
The question of how to stimulate such higher-order intellectual processes in children has never been more widely discussed. Tomorrow, the first ever thinking skills conference in Britain, bringing together more than 100 world experts, opens in Harrogate.
This autumn all key stage 3 teachers will, for the first time, be trained to teach pupils how to think. A flurry of new curriculum materials claim to promote thinking. So are we really on the verge of a thinking revolution? And, if we are, what difference might it make?
Picking your way through the various types of thinking skills on offer can be tricky, says Philip Adey, director of the centre for the advancement of thinking at King's College London, and proponent of several cognitive acceleration programmes for pupils in maths and science.
The Adey model of thinking skills is seen as traditional. It is based on the ideas of Jean Piaget, who believed children's minds spurt into multi-task thinking at around six, and conceptual or abstract thinking at around 14. It also draws on the ideas of Lev Vygotsky - that through questions and prompts adults can lift children earlier into more mature thinking.
But other psychologists think that this cognitive acceleration model is too narrow: they say thinking can be improved at any age. They want it emphasised from an early age and throughout the curriculum. They also point out that thinking involves creativity as well as the deductive reasoning stressed by their more traditional peers.
Meanwhile, a separate strand of teaching thinking, with its roots in philosophy not psychology, has been gaining popularity in schools. Proponents of philosophy for children - the best-known is Professor Robert Fisher of Brunel University - start from the words children use and their ideas, attempting through question and answer to improve the complexity of both.
Yet even while philosophers and psychologists argue about what is going on in children's brains, the fact remains that they have reached a consensus: that teaching thinking works, and that the crucial element of improving children's thinking is to improve their talking.
Thinking about thinking and then talking about it - psychologists call it metacognition - is at the heart of any reputable programme of thinking skills.
And there are some less than reputable ones around, says Professor Adey: "A lot of people are selling stuff to schools saying it's about the left brain and right brain and romantic music stimulating alpha and beta rhythms. Some of it is grossly oversimplified and some of it is crap, but teachers seem to lap it up."
This consensus exists thanks to a 1999 report by a prominent thinking skills specialist, Professor Carol McGuinness of Queen's University, Belfast. She was commissioned to write it by former education secretary David Blunkett's former standards guru, now Downing Street policy adviser, Michael Barber.
Despite repeated denunciations by then chief inspector Chris Woodhead, Barber, Blunkett and McGuinness between them propelled five types of thinking skills into the national curriculum in 2000 (see history above). The problem was that nobody in schools was quite sure how to teach them.
As a result, says Alison Wilcock, thinking skills consultant for York education authority, most schools did not teach them. "I think many schools don't really understand what thinking skills are all about." Part of her job has been to encourage the 600 KS3 teachers in York, one of 17 LEAs piloting the Government's KS3 strategy to improve teaching and learning in foundation subjects, to introduce thinking teaching into their classrooms.
The model they, and all other KS3 teachers in the coming academic year, are expected to use has been created in the grey area between philosophy and psychology. Drawing heavily on the work of Professor David Leat, formerly of Newcastle University and now promoting the KS3 programme, it emphasises that thinking skills should be taught across the curriculum, not just in a separate subject, through classroom teacher-led activities like mind-mapping, followed by discussion and reflection among pupils.
Perhaps inevitably, the philosophers and the psychologists feel their ideas have been severely watered down. They regret that thinking skills occupy just a twelfth of the KS3 foundation subjects programme. In any case, says Dr Carolyn Yates, an independent cognitive acceleration consultant, teaching thinking skills will only work in schools that are prepared to invest more in them than any national scheme.
For all experts agree that teaching thinking is a hard, long-term business. There are no quick fixes. You may see more articulacy in one year, but permanent change probably takes three. During that time there are two huge potential pitfalls, one for the children and one for the teacher.
The pitfall for children is that they learn to think in one place but fail to apply these skills across the curriculum. "Quite a lot of thinking skills work gets done in schools as a kind of short-term build-on, and it often gets a high excitement rating because it's something different and new, but often it doesn't last or spread very well," says Guy Claxton, professor of learning science at Bristol University.
"You can't just play some funny little games and then expect thinking about thinking to pop up into kids' consciousness wherever and whenever they need to think.
"It won't. You have to do things in lots of different contexts, they have to write thinking journals every week, you have to shift the culture of the classroom. Otherwise the thinking skills lock to the particular content."
The pitfall for teachers is that thinking often involves them letting pupils do more of the work. Thinking hard is hard, says Dr Yates. Children cannot do it at first. They need support but they also need teachers to resist the temptation to make it easier: "Teachers feel they have failed if children find things difficult. So they offer children clues, do anything to avoid a long silence in the classroom.
"But if you help children too much they don't do the thinking. I see far too many teachers working very hard and children just waiting for teachers to provide them with the answers."
So far, says Dr Yates, perhaps only 2 to 3 per cent of English schools have achieved successful thinking skills teaching across the whole school. In Scotland and Wales, where local authorities have thrown themselves into thinking skills, the proportion is slightly higher.
Will the thinking skills project succeed? The problem is that almost all thinking research has measured the success of highly-motivated teachers trained and monitored by experts.
The Government and experts in Harrogate this weekend still therefore need to answer one question: when the research ends, the high-quality thinking often ends too - so how can we ensure good teaching of thinking by the ordinary teacher in the average school?
1990s - growing body of research shows teaching thinking boosts children's classroom and exam performance.
1999 - David Blunkett strongly promotes teaching thinking.
2000 - Qualifications and Curriculum Authority adds five "thinking skills" to national curriculum (information-processing, reasoning, enquiry, creative thinking, evaluation).
2001 - 17 pilot authorities train key stage 3 foundation subject teachers in thinking.
Autumn 2002 - roll-out of "Teaching and Learning in the Foundation Subjects" throughout the country.
Evidence for the value of teaching thinking includes:
* Cognitive Acceleration in Science Education: 4,500 pupils across England boosted their key stage 3 national test scores and GCSE results in English, maths and science by - on average - a whole grade higher than they were predicted, after 30 hours teaching of thinking skills during Year 7 science.
* ACTS: 900 children in Northern Ireland aged nine to 11 showed much more complex thinking after teachers attended eight training days in teaching thinking across the curriculum.
* Year 1 children in Hammersmith and Fulham showed onaverage 18 months' to two years' progress on reasoning tests after a year of weekly 30-minute thinking lessons.
* Open University study out soon shows 10-year-olds improved in maths and science tests after teachers were trained in thinking.
* Philosophy for Children: American and British testing shows significant impact on basic skills and enthusiasm for learning.
SOME WAYS OF TEACHING THINKING
Instrumental Enrichment: Feuerstein. Israeli. Problem-solving activities taught three to five hours a week over two to three years. Developed 40 years ago for use with low-performing adolescents.
Philosophy for children: LipmanFisher. Teachers do "Socratic-style" complex questioning with pupils aged six to 18.
Subject-linked cognitive acceleration: Shayer and Adey. Promotes "cognitive conflict" in children, making them solve specific mathsscience problems which are slightly beyond their expected mental development.
Explicit "metacognition": children discuss thinking about thinking.
Thinking across the curriculum (Infusion): McGuinnessLeat . Teachers in different subjects plan activities to promote sequencing, analysing, planning, decision-making. Thinking must be explicitly discussed.
Cognitive Research Trust: De Bono. Popular with business but also used in schools, in particular De Bono's "Seven Thinking Hats" - denoting seven types of thinking: negative, positive, factual, imaginative, emotional, reflective and lessons asking pupils to consider situations from different points of view.