In legacy modular courses (last assessment Summer 2019), A Levels are split into two parts, with students within their first year of study pursuing an Advanced Subsidiary qualification, commonly referred to as an AS or AS Level, which can either serve as an independent qualification or contribute 50% of the marks towards a full A Level award. The second part is known as an A2 or A2 Level, which is generally more in-depth and academically rigorous than the AS. The AS and A2 marks are combined for a full A Level award. The A2 Level is not a qualification on its own, and must be accompanied with an AS Level in the same subject for certification. Due to the fact that AS Levels are considered less academically rigorous, the A* grade is reserved for those taking the subject to A2 standard, so only A2 units contribute to this grade. Additionally, students who are displeased with results from their AS units have the ability to resit. However, this has been criticised as nurturing a 'resit culture' and causing perceived 'grade inflation'.