I admire Kenny Gibson’s attempt (February 6) to defend his Cabinet Secretary and Parliament’s education committee. But the public must rely on the published record of the committee’s procedures and not what members believe she meant by “retire”.

The record of the committee’s meeting of December 17 last year shows that Fiona Hyslop aggregated the annual departure of 6,000 teachers (which no reasonable person would dispute) into a total of 24,000 over the lifetime of Parliament. But the annual departure is a mixture of temporary and permanent leavers from teaching. Many temporary leavers (for maternity and other reasons) will return when vacancies occur.

So it is false reasoning to add four times 2,000 temporary leavers to the four-year aggregate of around 16,000 permanent ones. The total over the period is, therefore, much less than 24,000. It is on that basis that I have been critical of the Cabinet Secretary and the education committee.

I want to reassure Mr Gibson that I am not seeking to be mischievous. Like him, I wish to see neither new teachers being unable to find permanent employment nor pupils unable to study the subjects of their choice because of teacher shortages. These extremes can be avoided if we have the most accurate possible forecasts of teacher supply and demand.

Douglas Weir, emeritus professor, Strathclyde University.