The University of Hong Kong has regained its status as Asia's top-ranking university in the latest QS World University Rankings, months after it was knocked off the top spot by the Hong Kong University of Science and Technology (HKUST) in the same research firm's Asia survey. QS researchers said the two surveys measured institutions differently and that the global version focused more on reputation, adding that HKUST is less known outside Asia. But they also warned that HKU, despite its strength in various aspects such as peer review and internationalisation, was weak in research output. '[HKU] ranks outside the top 150 in the citations per faculty component of the rankings,' QS head of research Ben Sowter said. In this category, HKU is ranked 172nd, while Chinese University stands at 177th and HKUST 222nd. This is much lower compared to the overall ranking that put HKU at 22nd, Chinese University at 37th and HKUST at 40th. Citations per faculty is a five-year ratio between the number of occasions a university's work is cited in major international academic resources and the number of its teaching and research faculty members. John Spinks, HKU's senior adviser to the vice-chancellor, said it was not surprising the number of citations per staff had fallen as the university was hiring new staff in anticipation of more students in 2012 under the new four-year undergraduate system. He said many staff were young and had not had time to build up research reputations. In May, HKUST was named best school in Asia in the QS Asian University Rankings, knocking HKU out of first place. QS said HKUST's impact was felt 'more quickly and profoundly in an Asian context than beyond'. An HKUST spokeswoman said it would continue to strive for teaching and research excellence. A spokesman for Baptist University, which leapt nearly 100 places from 342nd last year to 243rd overall this year but also dropped in the citation category, said: 'Rankings are not the goal of education.' The University of Cambridge remained at the top of the league table, followed by Harvard University and the Massachusetts Institute of Technology. A QS spokeswoman said the company was currently compiling a database which compared the tuition fees of universities.