In 1975, the economist Charles Goodhart wrote: ‘Any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes’. This claim is often colloquialised as ‘When a measure becomes a target, it ceases to be a good measure’.
An example of this is what happened when GP surgeries were given the target of reducing the number of days patients had to wait for an appointment. Rationally, surgeries responded by adopting a system of same-day appointments whereby patients had to phone on the morning they wanted to see a doctor. Of course there are never enough appointments for everyone who wants one, so the rationing of these became decided by who was able and prepared to press redial on their phone repeatedly at an early hour of the morning.
In schools, we are very familiar with the effects of Goodhart’s Law. The most obvious example are the various iterations of league tables which have resulted in so much gaming and distortion of educational priorities over the years.
The psychologist Donald T. Campbell at around the same time as Goodhart wrote: ‘The more any quantitative social indicator is used for social decision making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor’.
Campbell is describing the same effect as Goodhart, but with an emphasis on the pervasive psychological impact of measuring social phenomena. Goodhart thought in terms of incentives; Campbell in terms of subversion of the mind.
As teachers, we might reflect on how our behaviour has been steered by the explicit measurement and publication of ‘disadvantage gaps’: the intervention groups, labelling on seating plans, and priority marking of pupils who fall into a ‘group’ by virtue of how recently they have been allocated free-meals by the state.
Campbell and Goodhart’s insights relate to the use of quantified measures in social domains. However, their claims may equally be said to apply to the distorting effect of ideas being hijacked by policy-makers for the purposes of control or to influence behaviour.
We may state this as a version of Goodhart’s Law as follows: ‘The more any idea is used for policy making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor’.
I wrote a little about this here in relation to the corruption of curriculum ideas. I suggested that curriculum is the next example of a Big Idea which has been adopted by policy-makers and other powerful interest groups and instrumentalised in order to solve educational problems. I also suggested that this is an evolutionary process – that a Big Thing will emerge and serve a purpose in soothing the searing memories of the last Big Thing.
In response, the likes of Greg Ashman and David Didau have written some typically excellent and articulate posts. They both argue strongly for the importance of curricular thinking as being central to school improvement. And the thing is, I agree. The curriculum is, and should be, a key component in our thinking about schools.
But is has become faddish. When an idea which provides powerful insights for teachers is institutionalised as a tool for school improvement, or instrumentalised as an accountability process, or adopted as a policy goal, lethal mutations occur.
The curriculum should never have become a Big Thing. It should have remained a small, but important, thing which empowers professionals at the front line to engage in meaningful endeavour to improve the quality of education for the children in their care.
But we are where we are. I would encourage you to listen to those like Ashman and Didau who argue passionately for the centrality of curricular thinking. But I would also suggest that we have our eyes open to the corrupting effects on the social processes we care so much about.
You can read more about the evolutionary process of Next Big Things here.