Student visitor visas
If you are from a country which appears on the UK's Visa National List (known as visa nationals), you are required to apply for a Student Visitor Visa before travelling to the UK to attend residential meetings. You should apply for this from your nearest British Diplomatic Post, or Visa Application Centre (see web link below)
If you are a student from a country which does not appear on the Visa National List, (known as non-visa nationals) you are not required to obtain prior entry clearance and can travel to the UK and make your immigration application to an immigration officer when you land in the UK.
The Home Office UK Border Agency website provides essential information on applying for a visa.