well a social construct is a concept used in sociology. it basically means that it is constructed (built, made) by society, and doesn't necessarily exist objectively. what i think "science as a social construct" means in this context is that we accept science to be absolutely true, and that is why we have doctors and scientists and researchers and stuff like that. basically, we believe in science, as opposed to religion or whatever other belief systems exist. so, science as a social construct is saying that the whole process of science, the scientific ways of coming to conclusions and believing that we are right about the world, is spread around by society and everyone tells everyone else (by believing in it themselves, by teaching it in school, by using it as proof in court, etc.) that science is real and that it is the way we should look at things. remember, a social construct is basically something constructed by society. other examples of social constructs are class systems (people are not inherently of different classes, they may be born in different financial situations or may have different levels of intelligence, but class is made by groups of people that want to separate each other) and race (biologically proven that DNA within races varies more than DNA between races, we are all one species but choose to divide ourselves by outward skin color and features). hope this helps