Half of all Americans expect another country to emerge this century as the world's technology leader, according to a survey of United States public opinion released earlier this month by Duke University.

Although only 34 per cent of Americans gave themselves a grade of A or B for understanding 'the world of engineers and what they do,' 72 per cent expect the technological advancements of the 21st century to surpass those of the previous century.

Only 49 per cent predict the US will lead the way in producing these advances, according to the survey, titled 'Americans' Attitudes Toward Engineering and Engineering Challenges,' of 808 adults by Hart Research Associates, commissioned by Duke's Pratt School of Engineering.

The survey said that Americans with more education are even less optimistic about the likelihood the US being the world's technological leader in the 21st century. China was cited by 20 per cent of all the respondents as being most likely to assume this position, followed by Japan and Europe at 10 per cent each, and India at 4 per cent.

Among those who see a decline in America's ability to compete technologically, 55 per cent say the situation is temporary; 39 per cent say it is long term.

In response to a list of major engineering challenges facing the world, those surveyed gave highest priority to developing better medicines, providing clean water around the world and developing environmentally friendly power sources.

According to the survey the respondents were much less favourable to the idea of new immigration policies to attract foreign engineers and other technical experts. Still, 34 per cent said there is a need to reform visa and immigration policies to enable the US to attract and retain the best and brightest in science, technology, math and engineering.