A planned observation is probably the least accurate representation of teaching competency. Observations are sold to us as a means of identifying what professional development is required to make us even better at this teaching business. When they go well, we are kings of the world. When they go wrong, we’re told not to worry, it’s the lesson that is being graded, not the teacher. Then we’re bundled down a corridor where people in suits smile while they hiss words like “capability procedures”.

Obviously, we need to have some sort of process to determine teaching skill and ensure that learners are getting access to the best education. However, an hour-long planned performance with an audience member taking notes is just that: a performance. We know the rules of getting a reasonable grade and we try our best to follow them. But a real lesson goes from outstanding to “get your coat” and back again in the space of 10 minutes.

I have been observed many times and it never fails to keep me awake with worry. So when I got the email putting me on notice of another inspection, I cancelled everything I had scheduled for the afternoon and evening the day before in order to plan my lesson meticulously.

I woke up 24 hours before Observation Day to find the patio door hanging off its frame and a chunk of the casing missing from the outside. It looked as though someone had tried to force it open. It was only after calling the police that I thought about the implications of being home alone with my young son and the threat of an intruder. But my usual come-and-have-a-goif-you-think-you’re-hard-enough spirit returned as the adrenaline kicked in. Balance restored, I took my son to school.

I had anticipated a stressful day even before the patio door drama, as we were due to exchange contracts on a new house. It had been a lengthy process that had brought me to the brink of murder, but we were there. At 11am, I got a call to say that the deal had fallen through.

Then came the worst moment of that terrible day - I was informed that my son had injured himself and had been rushed off for emergency medical treatment. Although the accident was potentially fatal, he had been very lucky and I was allowed to take him home to be monitored overnight. The observation was the least of my worries. We got through the night and my son shook off his injury. I went off to work.

Exhausted, I cobbled together a lesson plan and welcomed the observer into my class, just pleased to be in an environment where I could leave the previous day’s traumas at the door.

The lesson went as well as could be expected and I got “a very high grade 2”, which I thought was fair, if not a bit generous. Although I am disappointed not to be an outstanding teacher, I think that session was an authentic representation of my classes. Bits were chaotic, bits were great, bits were less than perfect. A bit like my life.

Sarah Simons works in a large further education college in Mansfield