Table 1.

Levels of curriculum used in our analysis including the sources of evidence

Curriculum level	Description	Evidence
Intended	The formal statement of curriculum at school or national level	Curriculum documents
Taught	What a teacher actually delivers in the classroom	Literature review Insights from teacher communications
Learnt	What a student derives from the learning experience, learning outcomes	Literature review
Assessed	How the curriculum is assessed including constructive alignment with the intended curriculum	Published examination papers
Informal	Contributions made by areas of school life outside classroom teaching, e.g. science clubs and enrichment activities	Literature review Web search
Unstated/hidden	Elements of school culture and ethos	n/a