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  • Writer's pictureclairevharley

Correlation does not mean causation; Take care of the pennies and the pounds take care of themselves

Updated: Sep 2, 2023



I’ve been thinking a lot about the limitations middle and senior leaders have on what happens in schools. Don’t get me wrong, of course real, meaningful and sustained changes in school can be made through decisive leadership, but there are also many factors outside of the control of any adult in a school. If we introduce homework detentions and the number of pupils completing their homework increases at the same time, it’s a fair bet that the two are related, but what about larger changes in school improvement? How do we measure culture and how it changes? If school results go up, is this due to the actions of teachers? I think if we are thinking about school improvement, we are better off focusing on the pennies and letting the pounds take care of themselves…


In a lecture a few years ago I was introduced to the idea that correlation is not always causation. Simply put, this means that just because two things are happening at the same time, does not mean they are directly linked to an initiative we have introduced as senior leaders in school. The example my lecturer used can be seen in the graph below. What you’re looking at here is the correlation between the number of people who drowned in swimming pools in the USA and the number of films Nicholas Cage appeared in between 1990-2000. As you can see, there is a clear correlation between the two figures, but they are obviously unrelated and it would be inconceivable that Nicholas Cage should be investigated (although, I do think he has some questions to answer about City of Angels).




Fundamentally the point is that we cannot be too confident in our assumption that positive change is down to our own leadership or that failure in any given area is down solely to the person leading it. I've worked with leaders who I believe intentionally summarise the context, parameters and ‘best bets’ of a situation before they explain it to the senior leadership team. Like the Stoic philosophers before them, leaders who focus on what they can control and reflect upon their actions regularly are going to lead schools more effectively.


My biggest hurdle with the job last year was my inability to complete the School Improvement Plan (SIP). I honestly struggled to demonstrate the impact of my work because I would either overthink the data or feel as though it was too flimsy for me to make the jump from x to y when it was for something this important. This isn’t because I don’t get data or am unable to measure impact. I was doing my methodology for my EdD at the same time and so I know what I’m talking about… but perhaps that’s the issue. I know all too well that we can query the link between action and outcome to the point where it has no meaning. However, school leaders don’t have the privilege of having an epistemological crisis. We have to get on with it. My argument is that school improvement can take place through the old saying ‘if you take care of the pennies, the pounds take care of themselves’.


I work with middle leaders in my school and reflecting on this experience leads me to believe that if we want to develop others we can do so by giving clear, actionable steps in a given area of their role (the pennies) and model our own thought process when coaching them through a decision that will impact their subject/area of leadership (the pounds). Too much bigger picture thinking is not always helpful when someone is new to role or has to learn the ‘basics’ of middle leadership such as data analysis and quality assurance, but we can help people to find their way there by explain how these smaller steps will get us there in the end (James Clear would call these atomic habits).


Whilst writing this, I came across a blog by Joe Kirby that expertly sums up how we can evaluate how we can support teachers and direct teacher time and effort at a whole school level . Kirby tells us that we can influence school culture through consideration our understanding of our boundaries, reaction to pressure and goals (amongst many others) whilst spending less time concerned with external factors such as Ofsted and league tables. Whilst bigger picture thinking is important, there are simply so many variables that we will never truly know how x led to y, but by thinking about how we coach people through the everyday, the actionable and the manageable, the bigger picture is much more likely to fall into place.

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