We buy shiny new tablets, or we create a brilliant brain friendly programme, and – hey presto – students do better. These examples are comic, but the isn’t a quantum leap to our estimations when we evaluate school spending and such like. Take a look at these two graphs – as they’re graphs, we of course give them credence:Īnd there is this irrefutable evidence too! The perils of this lazy correlating pattern is brilliantly exposed by the website by Tyler Vigen aptly entitled ‘ Spurious Correlations‘ (thanks Stuart Kime for sharing this gem). We work backwards: we spent money on X, results improved generally = X caused the improvement and is worth the money. In our punitive accountability model we are not encouraged to honestly evaluate our interventions and their impact. Of course, schools ourselves are guilty of this basic failing when we analyze our evidence. Teachers don’t know what to believe and therefore they stop listening. We are forced to mediate a minefield of information.
CAUSALITY AND CORRELATION TRIAL
The evidence of a randomised controlled trial is matched up against political ideologies and personal prejudices at every step.
The debate about evidence and what has value is now part of the educational landscape. Most ‘evidence’ in schools, and education more widely, fails this test. We can ask the question: when do we attempt to put a control group and a treatment group in place for our latest innovations? To find evidence of causation, which is obviously very tricky, it requires decent controls being in place and a transparent statistical model that doesn’t fiddle the numbers to dredge up a positive result. Fundamentally, we must move toward better evaluating what we do. We are constantly being sold silver bullets whose evidence is based on loose correlation (or worse) and nothing like causation. This is of course of crucial important in schools. In practice, however, it remains difficult to clearly establish cause and effect, compared with establishing correlation.” ( Source: Australian Bureau of Statistics) smoking is correlated with alcoholism, but it does not cause alcoholism). smoking causes an increase in the risk of developing lung cancer), or it can correlate with another (e.g. Theoretically, the difference between the two types of relationships are easy to identify - an action or occurrence can cause another (e.g. This is also referred to as cause and effect. there is a causal relationship between the two events. A correlation between variables, however, does not automatically mean that the change in one variable is the cause of the change in the values of the other variable.Ĭausation indicates that one event is the result of the occurrence of the other event i.e. “Correlation is a statistical measure (expressed as a number) that describes the size and direction of a relationship between two or more variables. Now, I have a huge amount to learn about research evidence, but one of the turning points in my understanding was when I grasped the difference between correlation and causation (a threshold concept for research evidence): What we eventually need is a workforce of teachers who are critical consumers of research evidence and powerfully evidence-informed.
Networks like ResearchEd and organizations like the Institute of Effective Education provide ballast to still the ship against the rising tide of bullcrap. Reading the newly created Edudatalab was a boon in this regard. Reading excellent blogs like this one from Nick Rose certainly helps too. Working with experts like Professor Rob Coe and Stuart Kime in the RISE project helps.
CAUSALITY AND CORRELATION FULL
I have seen a fist full of dubious GCSE programmes that proclaim that their evidence will secure the GCSEs of your students’ dreams. The crumbling edifice that is the ‘learning pyramid’, or cone, or whatever it is branded as. I’ve had the ubiquitous learning styles foisted into my inbox. Discredited ideas keep bouncing back, recast and relabeled for the promise of a new generation of hard pressed teachers. In just the last couple of weeks I have been repeatedly ‘exposed’ to popular zombie edu-theories that simply won’t go die. In this job, you get to share a lot of teacher training materials and the like, coupled, or most often, decoupled from the evidence. I have had an interesting fortnight in my role as a school leader and Research-lead.
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