Public understanding of science (PUS) has become a portmanteau term used to cover a range of different visions of the relationship between scientific development and society. It includes concepts such as scientific literacy, public understanding, and public engagement. This entry discusses how concerns were first raised about the levels of scientific literacy in the population at large and attempts were made to gauge the extent of knowledge about science and technology. There was a growing perception that scientific advance was not always given the wholehearted support that scientific leaders thought it deserved. When it became clear that inadequate levels of knowledge and understanding were poorly correlated with lack of trust in science, scientists moved to foster greater public knowledge of their work through encouraging the ...