Misleading percentages

29th October 2004 at 01:00
I refer to the letter (TESS, October 8) from the Scottish Executive Education Department consultants regarding the data in STACs (Standard Tables and Charts). I am glad that S4-based data is to be fully included in the outputs next year.

There is no doubt that the relative values, progression values and particularly the Scatterplots are very helpful. However, it is unfortunate that the information downloaded by schools and the training notes put the use of passes as a percentage of presentations at the heart of assessing departmental performance. Some very strong statements are made on the basis of passes as a percentage of presentations, and my contention is that these conclusions have no real meaning and can be misleading.

For example, in maths there were 20 schools with national comparative deciles 1 or 2 for awards 1-2 at Standard grade in S4 that had relative values that were significantly negative. That is, the schools were in the top decile for pupil performance based on entries. From this the headteacher would be likely to conclude that the department was showing a "strong performance" and was "well above the national average".

In fact, the departments were showing poor performance as measured by the relative value - the definitive determinant of departmental performance.

There were also 16 schools in maths with NCDs of 8, 9, 10. These would be said to have "poor performance" and be "well below the national average".

Yet they had significantly positive relative values. They were actually showing "strong performance" not "weak performance". Thus, there is no link between comparative deciles and relative values.

Ron Mitchell

Education Services

Inverclyde Council

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