Services block parents
The council investigated five contracted out services in 24 of the 32 education authorities - school transport, meals, cleaning, grounds maintenance and building repairs.
Deirdre Hutton, the council's chairman, said the findings were "disappointing''. The report calls on councillors to ensure the monitoring of complaints is used to assess the way contracts are being implemented.
Mrs Hutton added: "Whether a service is delivered by an in-house team or a private company, the local authority is responsible for making sure the service specified is carried out. We are not optimistic that this is happening across Scottish local authorities."
The council's report says local authorities had too rosy a view of how easy it is for parents to make a complaint about public services.
A spokesperson for the Convention of Scottish Local Authorities described the study as "a one-sided account,'' adding that parents and pupils also had responsibility for such things as standards of behaviour on school buses and the cleanliness of school grounds and buildings.
She pointed out that councils were now in a transitional phase between compulsory tendering and the Government's "best value" regime, designed to seek service improvements.