Statistically insignificant?

One of the dangers at just looking at the numbers.

Progress 8 scores for most schools aren’t that different
There were over 300 schools with P8 scores between -0.05 and +0.05 – a difference of over 300 rank places (10% of schools) between the highest and lowest scoring of them. But what do these numbers mean?

Let’s say the score for School A was +0.05 and School B was -0.05. Taking the numbers at face value, one interpretation is that if you picked two pupils with the same KS2 attainment, the two pupils would have the same grades in seven of the subjects included in Attainment 8 but the pupil from School A would have one grade higher in one and only one subject than the pupil in School B.

Is this an educationally important difference?

It depends?

And talking of Progress 8 confidence intervals…

statistically-insignificant

xkcd: Error bars

Author: Terry Madeley

I enjoy reading about art and design, data, education and technology, and I work with student information systems.

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