Some schools grade lessons, some don’t. Some schools do unannounced drop-ins and learning walks. Some complete formal observations. Some schools do work scrutiny.

There are some schools that do learning walks, work scrutiny, formal lesson observations and the occasional colonoscopy just to be on the safe side.

Whichever way your leadership team attempt to measure performance and support staff development, one part of the process is similar in almost every school: the feedback.

Throughout my 12 years of teaching, the format has been the same. My line manager will observe me teach, and about halfway through the lesson they will leave the lesson with a brief thank you and a promise to catch up soon. A few days later I will sit down with them and they will ask the dreaded question: how did that go for you?

Cue five seconds of over-overthinking, in which you go through every possible scenario and direction this conversation could take in your mind.

Should you talk about all the positives you saw in your lesson and risk that person then turning around and disagreeing? This would make it look as if you hadn’t got a clue what was going on in your own classroom and only see the things you do well.

Should you identify all of the areas for improvement? But what if they didn’t see those? You’d be highlighting them and making yourself look like an awful teacher. No one wants to receive negative feedback, whether there’s a grade attached to it or not.

In my opinion the question "how did that go for you?" –  or any alternative in which someone makes you guess what’s on their piece of paper –  is extremely dangerous. And it certainly doesn’t develop an environment in which staff can analyse their lessons and plan their own improvements.

In his book, Coaching for Performance, John Whitmore said that "coaching is unlocking a person’s potential to maximise their growth". Schools need to embrace the power of coaching and allow teachers to lead the conversation when evaluating their lessons. You cannot do this by asking them a question to which you already know the answer. It can only be done though a coaching conversation in which staff feel safe and supported.

During this conversation the only times that the line manager should step in and discuss their observations is either to validate a teacher’s self-reflection or if there is a vast gulf between perception and reality. Line managers should guide the conversation using questions such as:

• What are the specific challenges for you with this class?
• What do you see as your main development points?
• What impact will this have on the students that you teach?

I wonder if anyone has ever been asked in one of these meetings: what more could I do to support you in developing this aspect of your performance?

I’m no fan of encouraging staff to use scripts for feedback, but I would suggest that the structure of the conversation is set and line managers are given formal training in how to feed back to ensure consistency across the school. In my opinion, the conversation should go along these lines:

Establish a starting point

Discuss how the students responded to the lesson. Was it any different to normal? Did particular students especially benefit from the approaches taken? What was the thinking behind taking these decisions and teaching the topic in this way?

Discuss the reality

How is your current workload? How do you find this class to be normally (remember, an additional presence in the room will always modify behaviour)? What are your key challenges at the moment?

Discuss future options

Which aspects of the lesson could have been adapted to further support students? How could this be achieved? Are there short-term or medium-term goals that could be set? Who could support the teacher in doing this?

Ask, what next?

How will the teacher share the successes and challenges during this process?

This coaching conversation should create a safe and supportive culture in which the teacher can learn to review in an effective and impactful way without fear of disagreement or judgement.

The key decision schools need to make is: what is the purpose of your lesson observations? Is it to judge teaching across the school and create data for inspections or is it to develop and support teachers?

Having experienced schools that have polarised opinions of this, I know what my belief is and I know which approach has the biggest effect on staff retention and student achievement.

Next time you observe a colleague, think first about how you could use feedback to develop a teacher who feels comfortable and safe making mistakes, and has the reflective skills to identify areas of achievement and development in a safe environment.

Being able to reflect and act upon this in an effective manner is a skill. Schools must not only create a culture in which staff feel safe and trusted, but they must also teach their teachers how to reflect and how to develop their own performance in the classroom.

Mike Harrowell is an assistant head at Regents International School, Pattaya, Thailand