I’m sorry I misunderstood but your original post said there was too much data. That’s what I tried to answer.
I can only speak of primary but it can be used by senior schools.
Each governor takes a subject or group of subjects. If that subject is in the Improvement Plan and is getting special attention, a governor monitors that part of the Improvement Plan and the subject.
They will make an appointment to see the subject leader or data lead and go through the data highlighting challenges, successes etc. Some GBs have a special meeting for this via T&L Committee. What is the data telling the governor(s)? What does progress look like? Do you understand how assessment works? Are outcomes close to predictions? Is progress 8 what was expected? Are the outcomes close? If not, why not? What’s going to be done about it? PP needs special attention. Look at what you need to know in terms of the Improvement Plan and whether the data is actually showing improvement or not. Each governor cannot do every subject so split it up. We had subject leaders attend GB meetings. Could you do this and ask questions? They also gave subject reports. Again you can query data on these. For example, if govt data shows poor progress for lower achievers, what is being done to improve this?
However, I still think you must rely on your SLT and senior staff to guide you. They should give you up to date info on everything in the Improvement Plan with data and commentary to back it up. So you might want to check lower, middle and high achiever progress, boy/girl progress, SEN, Pp progress and possibly staff training to deliver the desired outcomes etc. If the school isn’t meeting the SIP objectives, query this. The whole process is about getting behind the data to see what it’s telling you.
The school has experts in this field and it is still down to them to make a commentary and for you to delve under the surface by talking to staff, checking data against the SIP and recording questions and answers.
We have the HT report 10 days in advance and ask questions 7 days before the meeting. HT responds and the whole document goes to the GB. This is evidence for Ofsted that you are challenging and know your school and the SIP is being monitored. We also send in subject and SIP reports after visits. Surely the key to this is understanding what the data is telling you.
Any school has to triangulate the information or how do they know what it’s telling them? They are the leaders in this, not you. If they don’t know what the data is saying, how does the SIP work or self evaluation? I think your Advisor is expecting too much from Governors.
Hope this is a bit more what you are looking for. Other schools might work differently of course and some will involve governors a lot less. However good governors know their schools but the SLT must give you views on what the data is showing and then you monitor accuracy and look for over gilding!