The Ars Technica (10/6) outlines why states struggle so much with setting science standards. A group of scientific organizations and science teachers joined together to create the Next Generation Science Standards, which have been adopted by several states. The article highlights difficulties common to all science standards though. Unlike some subjects, learning new material in science often heavily relies on having prior knowledge so science standards that build off of each other have to be consistent for a significant period of time. Another problem with science standards is that the subject often becomes political in the US because lawmakers often have strong opinions about the science curriculum so they are regularly changed for political reasons.