: Selection bias exists in any study. The issue is not whether there is selection bias (there always is), but whether the selection bias is so great that it disqualifies the results. Unless there were a strong underlying pattern of increase by century, it would be almost impossible even with high selection bias to attain the resulting pattern of doubling by century.--[[User:Aschlafly|Andy Schlafly]] 10:51, 25 July 2010 (EDT) | : Selection bias exists in any study. The issue is not whether there is selection bias (there always is), but whether the selection bias is so great that it disqualifies the results. Unless there were a strong underlying pattern of increase by century, it would be almost impossible even with high selection bias to attain the resulting pattern of doubling by century.--[[User:Aschlafly|Andy Schlafly]] 10:51, 25 July 2010 (EDT) |