The charity's review of safeguards for looked-after children warned against an over-reliance on police checks, as only a relatively small proportion of abusers have criminal convictions. The report stated: "Rigorous checking of other information such as life histories, references and probing interviewing is also needed."
The review acknowledged that safeguards in boarding schools have been "transformed" in the past seven years, after an influential report into protection for children living away from home.
The latest report, however, also urged better recording, handling and sharing of "soft" information, such as previous arrests which may not have led to convictions.
This echoed recommendations made in June in the Bichard inquiry into the Soham murders.
Catherine Baines, who co-wrote the report, the result of a two-year study, said it was not good enough to rely on police checks.
She said: "Good recruitment practice, such as thorough checking of references, is needed for all people working with children but particularly those with unsupervised access."
Marian Stuart, the report's other author, said experts estimated that only one in 50 sexual offences led to a criminal conviction. The incidence of child abuse generallt was more widespread than was usually acknowledged.
Ms Baines also called for boarding schools to provide parents with information on staff vetting. The study reviewed improvements during the past seven years in safeguards for children living away from home. Twenty principal recommendations and 139 others were laid out by Sir William Utting, the former chief inspector of social services, in 1997.
His report, People Like Us, followed allegations of abuse in children's homes and foster care in North Wales. The report said that since Utting, welfare inspections, a new registration system, more training and better regulation had been introduced.
But it described co-ordination between health, education and welfare services for disabled children as poor. It also said policy for children with emotional and behavioural difficulties should be reviewed urgently.
Adrian Underwood, national director of the Boarding Schools' Association, welcomed the report and said it proved the institutions had "put their house in order". "While we do not want to be complacent, we took the Utting report on board in 1997 and made the required changes," he said.
Progress on the safeguards for children living away from home is available from www.jrf.org.uk