Head teacher explains why school is ranked bottom for GCSEs
26 January 2012 Last updated at 22:37 GMT
Just one in 15 (6.5%) pupils starting secondary school in England "behind" for their age goes on to get five good GCSEs including English and maths, official data shows.
Government figures published as part of secondary school league tables suggests the majority of schools are failing struggling pupils.
The worst performing school at GCSE was St Aldhelm's Academy in Poole, which became an academy in 2010. Just 3% of pupils achieved five GCSEs above grade C.
Across the rest of Poole and in neighbouring Bournemouth that figure was 57%.
The school's principal, Cheryl Heron, offered an explanation to BBC South's Chris Robinson.