Desk research against primary sources, with the issuing authority linked where a page states an official fee, rule or deadline.
The six-point scale looks like one verdict, but the inspection behind it scores teaching quality, student achievement, leadership and wellbeing as separate strands. A school can carry an overall Good while sitting weak in exactly the strand that matters to your child — often wellbeing, or provision for a particular age group — and that only becomes visible once you read the full published report rather than the single headline word.
The rating also carries financial teeth: a school must be assessed Good or above before it is permitted to apply for a fee increase, so a school stuck at Acceptable has less room to raise prices than parents often assume. Outstanding is reserved for roughly 10% of schools, so treat it as a genuinely rare finding rather than a phrase a prospectus uses loosely to describe itself.