sentences:  Robert Booth of "The Guardian" wrote that in 2009 the school "was undergoing a period of turmoil" as several parents criticized the operation of the school, leading to a parental group criticizing Cognita that was established in 2011.In August 2012 Cognita acquired the Charteris Sports Centre in London as a facility for Southbank International School which is let out to the community in non-school time.In 2013, students from the school performed at the United States Academic Decathlon.