Dr Chris Yapp, NACE patron

The need for reform of the assessment is system is now being well argued at the national level. It is important to remember that the current assessment framework and exam results are an important part of the accountability framework by which schools are judged. The issue I wish to address here is: how does any new assessment framework that is developed impact on the accountability of schools? Importantly, what issues and problems of the current approach could be addressed by a novel approach?

If I ask you about the ethos of your school, I would probably have no difficulty in achieving consensus that “every child should be able to reach their full potential” would be a core value of teachers and educational leaders near universally. However, if I suggest that 80% of children should achieve their full potential in education by 2025, how would you react?

My experience is that few are comfortable with the target, even though you can’t reach 100% unless you go through 80% at some point. It would be easy to be cynical that teachers may aspire to the vision but react against trying to achieve it. There are numerous reasons why professionals are uncomfortable with this problem. First, how do you measure potential? Importantly, does the assessment framework reflect both achievement and potential?

There is an economic model, Goodhart’s Law, which has a long history of precedent in different fields and is now more widely understood as a general problem. The usual formulation of the law is: “When a measure becomes a target, it ceases to be a good measure.”

Consider the following example: 80% of children should reach Level X by Year Y.

Apart from agreeing how that is measured, there is another big problem to be addressed. Once a measure becomes a target it can be “gamed”.

Consider two schools with similar catchment areas and performance facing this as a target. 

In the first, the leadership team focuses resources on all children and their development and reaches 78% on the timescale set.

In the second, 10% of children are given minimum support and the resources are focused on the remaining 90%. The school achieves 82%.

Which is the better school? Which would you want to work in? Which would you want your children to go to?

In short, targets can distort ethos and with it the morale and self-worth of professionals. It happens with accounting in the private sector, in reward mechanisms and many other walks of life. My experience is that once you understand Goodhart’s Law you start to see it everywhere.

One of my favourite quotes of Sir Claus Moser sums it up well: “If you can measure the same thing in two different ways, you'll get two different answers.” 

The different components of education are heavily interdependent. Teacher development is heavily dependent on curriculum design, which in turn is heavily dependent on assessment. Attempting to reform one without understanding the impact on the other parts is fraught with difficulties.

So, I welcome a focus on reforming assessment in schools. For me, it is long overdue. However, in the context of our 21st century economy and society we need to be more explicit about the ethos of our education system and its individual institutions. I believe in accountability systems, but they must be driven by ethos, not targets. The assessment measures that are developed need to reflect our societal and economic goals for education itself.

If our ethos is to optimise pupil achievement, the wise words of Plato come to mind: “Do not train a child to learn by force or harshness, but direct them to it by what amuses their minds, so that you may be better able to discover with accuracy the peculiar bent of the genius of each.”

• Read more from our “rethinking assessment” series
• Share your experiences of remote feedback and assessment: NACE member survey