Education data has been in a state of flux for some time. Undoubtedly, this has partly been down to changes within the education system - from curriculum adjustments to incorporating new performance measures - and the need to reflect these.

However, more often than not, school leaders are being left in the dark as to how to deal with critical pieces of information that are essential to measuring outcomes, drawing comparisons with other schools and self-evaluating.

For instance, for secondary schools, one of the most important data elements to get to grips with quickly is the key stage 2 (KS2) starting point for each student.

Yet there is no simple way to gather this information quickly.

For current Years 10 and 11, we know that the starting point will be the KS2 fine level - which is a measure that primary schools have nothing to do with. Put simply, the KS2 fine level depends on the marks achieved on a Sats paper, and how many marks there were between each level.

In theory, this data has to come from the Key to Success or NCA Tools website (it depends on when you downloaded the data which site it will have been). But in practice, you can also pay to get the information from other sources. It is confusing, especially when the Department for Education does eventually confirm which fine level you should have been working with - but only in June, just before the students leave.

Data issues ‘just the tip of the iceberg’

For other year groups, getting hold of the data is easier, as we can download the KS2 scaled scores through the same channels. But there has been no decision as to which combination of scaled scores will be used to underpin progress measures in the future. Common sense says we should probably take an average of reading and maths, but there is also a grammar, spelling and punctuation scaled score that could or could not be incorporated. So, we simply don’t know for sure.

Another question I am often asked is why national statistics vary from source to source: why does Ofsted sometimes treat data differently to the DfE? Why, even in the same document, are national figures calculated from different source data (sometimes including all schools, or just state-funded schools)? Why do we have an Analyse School Performance (ASP) document and an Inspection Data Summary Report (IDSR), as well as the public-facing performance tables and statistical first releases?

These things are just the tip of the iceberg; complexities seem to exist at every turn.

For those who are completely immersed in the world of education data, the current situation is just about manageable, but in an environment where all teachers should be using the data to help paint a clear picture for future planning and evaluation, these issues cloud the ability to make informed and rational decisions.

So, what can be done about it? Here are a few recommendations:

1. The DfE needs to provide schools with pupils’ progress starting points in a more timely and useful fashion. For example, secondary schools would really appreciate this clarity by the end of Year 9, in time for Year 10.

2. The DfE should inform schools about how Progress 8 will be measured using KS2 scaled scores as the baseline, instead of KS2 fine-levels.

3. Make KS4 prior attainment more readily available and easy to download in time for students starting KS5.

4. Make national statistics clearer, more concise and less ambiguous in their calculations.

Peter Atherton is chief data officer at Minsthorpe Community College, Wakefield. He has more than 15 years’ experience in analysing education data. He blogs at minsthorpedata.com