Ranges and purposive selection

Amongst candidates for the EQE C paper of 2010 a lot of discusion is going on about how to attack the ranges in claims 4 and 5. Is it possible to do a novelty attack or do we need inventive step (workshop modification, equivalent alternative or maybe a second document). Today I will give you some advice about how to deal with ranges in the exam (in your daily patent work, you should do the same).

The situation in the exam was as follows:
- Claim 4: 1 mm - 3 mm
- Claim 5(4): less than 1.8 mm (thus 1 mm - 1.8 mm)
- A3: 0.1 mm - 20 mm, 0.5 mm - 2.5 mm and 1.5 mm - 2 mm
- A4: 0.1 mm - 20 mm
- A6: 0.1 mm - 4 mm, 0.9 mm - 4 mm and 0.1 (and/or 0.9) mm - 2 mm

The relevant part of the Guidelines is GL C-IV 9.8 (ii) which gives three criteria for considering a sub-range selected from a broader numerical range to be novel.