The quality of maths and science education in South Africa has been ranked among the worst in the world ... again. The World Economic Forum released its latest Global Competitiveness Index recently and of the 140 economies listed, South Africa ranked last for the second year in a row.The study measured infrastructure, health and primary education and technological readiness among others, with a multitude of top businessmen being polled on their perceptions of various countries.Department of Basic Education spokesman Elijah Mhlanga rubbished the index as having "no credibility" because it is not "based on research". He claimed the index was an attack on South Africa.He said: "We don't want someone to rank us based on a questionnaire they filled out in some comfortable office. I don't think they even read the minister's report to see the progress made."He said the rankings also failed to include enough countries.He added: "It's an attack on the country by business people."There are challenges, but let's measure our progress using tools and methods."But Basil Manuel, the president of the National Professional Teachers' Organisation, said the index should not be so quickly rejected.He said: "There is a problem, and how we approach it is important. I believe a balance of views is good."It's not necessarily a true reflection. [But] we must not discount the views of captains of industry. How they see education is important."Manuel said there was a lack of quality maths and science teachers in the country.Education specialist Graeme Bloch believes HF Verwoerd's policies limited blacks' understanding of mathematics.He said: "I think we are doing very badly. It is not based on opinions, it is based on reality. There are lots of reasons [for the low ranking]. I am not blaming history but I am being realistic about history." Additional reporting by Philani Nombembe..