A report from Her Majesty's Chief Inspector of Schools published this week says that some headteachers do this intentionally, and some are just incompetent.
In many schools, monitoring and evaluating school performance are are the weakest areas of the governors' work, says the inspection agency. In some, governors think they are fulfiling their monitoring role, but are not doing it effectively - often because the headteacher is keeping the true picture from them.
The report draws on evidence from schools in special measures and serious weaknesses to highlight ways governors can be supported to become more effective.
Failing schools often have failing governing bodies, which "have become unquestioning about the school's work," notes the report. But where weak governing bodies receive help, improvements usually follow.
OFSTED is positive about the support most local education authorities offer governors, by helping with action plans and recruiting new governors with particular skills.
It also notes that, while good paperwork does not guarantee effective governance, getting school policies, aims and schemes of work right can help to clarify and guide governors' work.
"In a significant proportion of schools made subject to special measures, and where governance was weak, governors were unsure of the school's basic aims, ill-informed about the contents of the school development plan, insufficiently involved in the formulation of schools' policies and procedures, and unclear about their role," noted the inspectors.
"Making It Better: Improving School Governance" www.ofsted.gov.uk