Some schools could be inspected twice on the same day by Ofsted under plans to test the reliability of its findings.
The new arrangements are to be piloted this term, with two senior officials from the inspection body visiting the same institution and comparing their judgements.
If approved, they could form part of the shorter but more frequent inspection regime for schools, which is due to be introduced from September.
"There will be a small number of pilots this term to investigate whether two inspectors come up with the same conclusions," a spokeswoman told BBC News.
She added that there was no suggestion they would be used for all the shorter inspections but they could be "an occasional feature as part of the quality assurance process".
Sean Harford, Ofsted's national director for schools, has admitted not enough has been done to ensure reliability.
He said the inspection body does not ensure the same judgement is arrived at by different inspectors.
Mary Bousted, general secretary of the Association of Teachers and Lecturers teaching union, called for Ofsted's work to be externally verified.
Brian Lightman, general secretary of the Association of School and College Leaders, welcomed the fact that the inspectorate had recognised there was a problem with reliability and is taking steps to address it.
He added that inaccurate inspection ratings can have "disastrous" consequences for a school.
Sean Harford said the quality of its inspection judgements was "of the utmost importance to Ofsted".
"We go to great lengths, through our existing quality assurance process to ensure that inspectors make judgements which are rigorously based on the evidence gathered," he remarked.
These measures include site visits by senior inspectors to test evidence, data analysis and the analysis of all inspection reports to ensure the text matches the overall grade.
Posted by Alan Douglas