In the middle
Your GCSE or A-level pupils will have departed in the summer, trailing streams of data behind them. If you are a head of subject, your department inquest is probably already under way. It is easy to be sidetracked by banner headlines and the Government's unrealistic expectation of year-on-year improvement. Each subject will have had an impact on the overall school statistic, but it is your job to pick out the data that yields more quality information. The breakdown of marks will allow you to look closely at candidates' strengths and weaknesses, while value added data will answer your questions about possible underachievement and which of your colleagues need support.
As for the new arrivals joining "big" school, they will be blissfully unaware of the cartloads of data that accompany them. Teacher expectations are prone to being dented by crude data, but Key Stage 2 results can be dangerously unreliable and graphs depicting cognitive ability, verbal scores etc. can easily cloud the teacher's first judgment.
If you are a pastoral leader, you are likely to be more interested in the "softer" data that comes from primary teachers and outside agencies. The record of behaviour of individual children, social services involvement and home circumstances, for example, is often the sort of "soft" data that will help you decipher the "hard" facts.
Ultimately, the best data is probably the kind you create yourself. For example, quality formative assessment coupled with a central database of children's interests is a powerful mix that describes the whole child. It will have significant impact on standards and pupilteacher relationships.
Perhaps caution and a healthy degree of scepticism are the best attitude to take towards data at this time of year. Whatever you do, the key to improvement is your ability to transform information into insight.
Deputy head, Redbridge Community School, Southampton