The TV presenter Andrew Neil’s assertion back in 2017 on the BBC’s Sunday Politics show that “after a decade of SNP rule, one in five Scots pupils leave primary school functionally illiterate” has landed both him and the broadcaster in hot water.

Yesterday, media watchdog Ofcom found that his statistical claim - made during an interview with former SNP leader Alex Salmond - was not accurate or based on any official source, and misled viewers during the build-up to elections in 2017.

However, Neil was far from contrite in his representations to Ofcom, saying: “Evidence is strong that illiteracy in Scottish schools is still deeply embedded in the system and that, far from improving, is likely getting worse, even after 10 years of SNP government.”

Literacy levels in Scotland

So what do we know about literacy levels in Scotland, and is illiteracy “deeply embedded”?

Here, we take a look:

What do we know about children’s reading and writing ability?

There are a few ways that this information is gathered. The Scottish government takes part in Programme for International Student Assessment (Pisa) education rankings, which look at the reading, maths and science performance of 15-year-olds.

The country also, between 2011 and 2016, ran the Scottish Survey of Literacy and Numeracy (SSLN) - a sample survey that looked at pupils’ performance in literacy and numeracy in alternate years.

Then there are the figures on the proportion of Scottish pupils leaving school with different levels of literacy qualification.

Finally, there are the new figures which the Scottish government has started to collect on teachers’ judgements about whether or not pupils in P1, P4, P7 and S3 are hitting the expected level in reading and writing for their age and stage.

What do those figures tell us about whether children leaving primary are ‘functionally literate’?

It is hard to answer that question because that is not the way the figures are recorded. In the case of primary pupils, the statistics that are collected tell you whether or not they are performing at the expected level for their age and stage, but not whether or not they are functionally literate.

Which level of Curriculum for Excellence (CfE) they have to hit before being deemed functionally literate is not clear, just as it is not clear which level of literacy qualification pupils in secondary need to attain in order to be deemed functionally literate.

However, it is probably fair to say that we would like children to be functionally literate - so they know enough reading and writing to function effectively in society - by the end of primary.

So are Scottish pupils hitting the expected literacy level at the end of primary?

According to the latest figures - the teacher-judgment data published in December - around a third are not. The figures show that last year overall 70 per cent of pupils achieved the expected literacy level by the end of P7, meaning 30 per cent did not.

The proportion of P7 children hitting the expected level for writing was 73 per cent; the proportion of P7 children hitting the expected level for reading was 79 per cent.

These figures are deemed ‘data under development” though, so what did the last round of the Scottish Survey of Literacy and Numeracy show?

The SSLN was discontinued in 2017 and replaced by the new teacher judgement data. However the final round of the SSLN published that year showed that 88 per cent of P7 pupils performed well or very well or beyond the level in reading in 2016 (a drop of two percentage points on the 2012 figures) and 65 per cent were performing well, very well or beyond the level for writing in 2016 (a drop of seven percentage points on the 2012 figures).

What are the P7 pupils who achieve CfE Level 2 supposed to be able to do when it comes to reading and writing?

The literacy benchmarks set out what pupils are supposed to be able to do in order to achieve the different CfE levels. In order to achieve Level 2 writing at the end of P7, they need to demonstrate a range of skills including being able to “spell most of the words [they] need to communicate”; write “most sentences in a grammatically accurate way”; write “in a fluent and legible way” and use “a range of punctuation”.

When it comes to reading to achieve Level 2, they have to be able to, for instance, read “with fluency, understanding and expression using appropriate pace and tone”; “demonstrate understanding of texts”; and “know the difference between fact and opinion”.

What does the other literacy data that the government collects show?

The other data does not refer to primary school children or attainment in P7, but it is worth mentioning. So, government figures show that last year 96.3 per cent of school leavers achieved the equivalent of a National 3 or better in literacy; 94.3 per cent achieved the equivalent of a National 4 or better in literacy; and 81.6 per cent achieved the equivalent of a National 5 or better.

To achieve a National 4 literacy unit, pupils have to be able to write straightforward, technically accurate, texts; read and understand straightforward word-based texts; and listen to and understand straightforward spoken communication.

That leaves Pisa - what does it show?

The latest Pisa results came out in 2016 and were based on data gathered in 2015. Scotland ranked third of the four home nations in each category - science, maths and reading - with only Wales doing worse. In 2012, when the previous round of Pisa tests took place, Scotland was top in reading and maths.

Scotland is now considered “average” in reading, science and maths. In 2012, it was “above average” for reading and science.