Proving our added value

Statistics show that the teaching provided by St Mary's School, Cambridge over a two year period boosts each student’s GCSE results by, on average, more than half a grade.

At the start of Year 10 all students undertake the computer-based CEM (Centre for Evaluation and Monitoring) YELLIS assessment, which enables the school to obtain a more detailed picture of each individual’s academic profile and potential across different subjects. The assessment also provides the school with an idea of what GCSE grades each student is likely to achieve in each subject based on a comparison with the results of past students of similar academic profiles. When students collect their GCSE results at the end of Year 11 the school is able to compare the girls’ actual achievements at GCSE level with the grades they were predicted – in essence assessing whether the school has added value to its students’ learning over the two year period. 

Headmistress, Charlotte Avery, explained: “Although we are a selective school we do take enormous pride in offering places to students of a wider ability range than other local independent schools, and we are fortunate to have the freedom and resource to invest in each and every student. Our girls benefit from the rigorous academic environment, the tailored support we offer and, indeed, our pastoral programme to achieve, on average, 0.6 of a grade higher than they otherwise would. By way of example, from our 2016 cohort, 135 papers that were predicted to be awarded a B grade were instead awarded either an A grade (81 papers) or even an A* grade (54 papers); clearly this added value makes such a positive difference and propels our students’ academic accomplishment.”

Changing grade boundaries and different numbers of students sitting GCSEs in different subjects each year, among other factors, affect the national picture of schools’ over- or under-achievement from one year to the next. In addition to the teaching provided by a school, factors such as students’ effort levels, personal health, home lives, and availability of help and support from others, will also impact a school’s over- or under-achievement, and so its added value ‘score’ too. CEM provides indicators, or ‘confidence limits’, to represent the extent to which a school’s positive or negative score is likely to have been due mainly to chance, or whether a school can be confident that its scores are directly attributable to their teaching provision.

In 2016, CEM is confident that any value added scores more than 0.2 of a grade above or below what was expected are as result of the schools’ teaching provision and availability of resources. Within this context, St Mary’s School, Cambridge’s 2016 achievement of, on average, 0.6 of a grade higher than expectations, shows that the school’s teaching provision added substantial value to its students’ GCSE outcomes.

Ms Avery continued: “I am pleased to note that this accomplishment relates to every part of our school community, for both our day girls and our boarders, our brightest students and those benefitting from learning support or for whom English may not be their primary language. Whichever way you might ‘group’ our girls, this ‘over-achievement’ remains: each group achieved higher grades, on average, than was anticipated from that group of girls’ predicted grades. I was also encouraged to see that the achievement spans the range of subjects at this level, too. Average grades achieved in Music, German, Drama, and Design and Technology were all a whole grade above what was predicted, and Biology, Chemistry and Physics grades achieved were all more than half a grade higher than forecast, as were those in English Language, English Literature, and the humanities. We are a school that confidently promises to value, uphold, listen to and support each student. Although academic excellence is but one tenet of this promise, I am thrilled to be able to shout about our academic successes in this way.”