"The assessment of GCSE Science from September 2006 is based on:

• Three short, objective tests, covering the modules in groups of three
• A terminal 'Ideas in context' exam with pre-release stimulus material
• Internal assessment of practical skills:
  - analysis and interpretation of primary data collected in class
  - a case study of a topical scientific issue related to the content of the course.

The Case Study is an individual student report of a topical science-related issue. Students must use information critically from a range of sources to consider different viewpoints, before reaching their own conclusion based on the evidence. They may present their Case study in a variety of ways. The Case Study has proved to be motivating for student of all abilities."  

http://www.21stcenturyscience.org/assess/core-science,899,NA.html