Science in schooling has for the first time been recently considered as a verified whole for the 10 or 12 of its compulsory years, rather than for a limited sector of schooling or for a particular group of students. This has also been occurring as part of a wider review and plan for the whole curriculum of schooling. A framework has been provided consisting of a matrix of strands of intended content for learning across a number of levels approximating the years of schooling. There is a sense and expectation of continuous progression in the learning of science. Earlier notions of progression in science curricula are explored and compared with what has now appeared in the national curricula in England and Wales, New Zealand and Australia. The notions of curriculum opportunity and curriculum purpose for science education are introduced as factors that would lead to a shift in the sense of progression from a focus on Science itself to an emphasis on the learners' changing need of Science as they progress through the years of schooling.