The finding, based on visits to specialist business and enterprise schools, is hardly surprising since there is no universally accepted definition of enterprise learning which can involve creativity and managing risk.
But the Government is keen to promote an enterprise culture and wants there to be stronger links between businesses and schools, so that pupils have a better understanding of their future role and responsibilities.
From this month, schools must make provision for all key stage 4 students to develop enterprise skills under statutory requirements for work-related learning.
And from next year the Department for Education and Skills plans to fund the equivalent of five days of enterprise learning for all KS4 pupils.
The aim is to develop children's ability to innovate, be creative and to manage risk as well as their understanding of the worlds of finance and business. Inspectors from the Office for Standards in Education who visited the 33 specialist business and enterprise schools piloting enterprise learning found that there was no blueprint. Despite this examples of good practice were observed in the majority of schools.
In one school pupils produced and sold a CD-Rom on educational attractions in London. In another, art students were asked to produce a business plan for the creation of a large mural to be displayed in Spitalfields market.
But most schools had a narrow view of enterprise, confining it to developing entrepreneurial skills or learning through links with businesses.
"Only half the schools had an explicit and commonly understood definition of enterprise learning. This was impeding progress," said Ofsted.
"The least effective schools failed to recognise that enterprise education had important implications for teaching and learning styles."
Inspectors said that in schools making the most effective provision, an enterprise ethos permeated teaching and learning across the curriculum.
Only a minority of schools though had identified learning outcomes in terms of pupils' enterprise knowledge, understanding, skills and attributes and very few assessed their progress effectively.
The report recommends schools develop better assessment and establish a clear definition, understood by everyone at school.
It says the Qualifications and Curriculum Authority should give greater recognition to enterprise learning in vocational qualifications and that the DfES should compare cost-effectiveness to recommend the best approaches in the future.
Learning to be enterprising. An evaluation of enterprise learning at key stage 4 is available at www.ofsted.gov.uk