As a means of achieving scientific literacy goals in society, the last two decades have witnessed international science curriculum redevelopment that increasingly advocates a 'new look' inquiry-based approach to learning. This paper reports on the nature of the student-experienced curriculum where secondary school students are learning under a national curriculum that is intent on promoting students' knowledge and capabilities in authentic scientific inquiry, that is, inquiry that properly reflects that practiced by members of scientific communities. Using a multiple case study approach, this study found that layers of curriculum interpretation from several 'sites of influence' both outside and inside of the schools have a strong bearing on the curriculum enacted by teachers and actually experienced by the students, and runs counter to the aims of the national curriculum policy. Over-emphasis on fair testing limits students' exposure to the full range of methods that scientists use in practice, and standards-based assessment using planning templates, exemplar assessment schedules and restricted opportunities for full investigations in different contexts tends to reduce student learning about experimental design to an exercise in 'following the rules'. These classroom realities have implications for students' understanding of the nature of authentic scientific inquiry and support claims that school science is still far removed from real science.