Many of us cut our teeth as teachers in the lessons we dreaded the most - covering for absent colleagues. As a rookie teacher, it was the uncertainty that got to you first. You'd head off to the appointed room - often for an unfamiliar subject in an unfamiliar outpost of the school - not knowing quite what to expect in terms of the class or the cover work.
Worst would be the wordsearch - that desperate and unconvincing attempt to shoehorn subject relevance into a format pupils are supposed to find interesting. They never do. With a rising sense of sickness, you'd notice the first hands going up eight minutes into a double lesson and await the gleefully uttered phrase: "Sir, I've finished."
As our confidence grew, we knew the only real solution was to ditch the work that had been set and unleash our personal armoury of ready-made alternative lessons. This is where I developed a quite shameless stand-in lesson, loosely based on exploring astrology. I would talk about the nonsense of the star signs, feigning both contempt for this pseudo-science mixed with apparently lofty knowledge of each star sign. "Sagittarius," I'd say, "is supposed to have a reputation for being outgoing, for loving friendship, for being bad at telling lies."
As a confused teenager, I'd read some hokey guide to astrology and recalled enough to quack it with authority. I'd witter away until I noticed some kid at the back nudge his friend and mouth: "This is me." Then, with a Derren Brown-style flurry of drama, I'd point at the nudging child and say: "You, Stephen, are a Sagittarian." Stephen would stammer his amazed assent, and the myth would start to build that young Mr Barton had an uncanny kind of gift. If he could do this, what else might he know about your inner thoughts?
It's pathetic, if entertaining, to recall this nonsense now. From an age long before the accountability of schemes of work and value-added scores, my priority was simply - in the absence of decent cover work - to keep a class amused for the requisite lesson and hope that they might learn some listening skills in the process.
Doing cover was never, of course, the best use of a teacher's time. As the Training and Development Agency for Schools' website tells us: "Being asked to cover can have a negative impact on the time teachers have available for lesson planning. Schools that have low or no teacher cover report happier staff, teaching better lessons."
This view is cemented in the 2003 workforce deal between government and teacher unions (agreed with all but the National Union of Teachers). The early phase stopped teachers doing tasks such as photocopying, counting money for school trips, invigilating external exams and putting up displays. Now the final phase of the agreement hoves into view: from September this year, teachers should only "rarely" be doing cover.
The exact definition of "rarely" is the matter of a semantic tussle. But it looks likely that doing cover will be a thing of the past for all teachers from September. Even if it is allowed, it will only be up to a few hours over a whole year.
Should we rejoice at never again turning up to find an inadequate wordsearch, an unfathomable textbook, a half-baked set of instructions for an activity that pupils have already done?
The problem is that if we really do believe that every child matters, then a hard line on "cover" - that is, zero cover - may end up impoverishing the quality of education for many of our pupils. Trips and visits, conferences for pupils and teachers, celebratory assemblies at which we want tutors to attend at a time when they might already have been scheduled to teach - all of these enriching aspects of school life will be threatened in schools that cannot afford to employ a new army of support staff to cover lessons. And if I were the parent of a child taught by a teacher who was off on long-term sick leave, I might object to my child having a succession of lessons with no teacher.
So, while it clearly makes no sense for most teachers to spend their time doing cover, some of us believe cover is a prerequisite for some teachers - by which I mean those paid on the leadership spine.
For us, cover goes with the territory. We should be taking cover lessons as a way of overseeing behaviour in the absence of the class teacher, monitoring students' work, maintaining our credibility with staff and ensuring that, despite the absence of their regular teacher, our pupils are getting a high-quality education. More bluntly, there will always be some classes, some uneasy cabal of characters, who will end up generating far more grief and disruption if they aren't covered by the besuited heavy mob.
We should recall from the Government's imposition of teaching and learning responsibilities how disastrous straitjacket policymaking can prove. For the benefit of discipline and pupil progress, schools need the flexibility to build cover into the contracts of some key teachers. This is common sense, as any Sagittarian will confirm.
Geoff Barton, Headteacher, King Edward VI School, Bury St Edmunds, Suffolk.