语义学技术使得数字和代表其含义的信息紧紧绑定。没有了语境,一个数字可能是很危险的事情。例如1991年,美国航空航天局(NASA)的耗资1亿2千5百万美金的火星气象卫星计划的失败,正是因为一组工程师在使用了英制度量,而另一组却使用的是公制单位。结果,飞船被下令围绕一个危险的低纬度进行环绕飞行,从而导致其在火星大气中焚毁。 Semantic techniques make the numbers bind tightly to the information that represents their meaning. Without context, a number can be very dangerous. For example, NASA’s $ 125 million Mars Meteorological Satellite program failed in 1991, precisely because one group of engineers was using imperial metrics while the other team was using Metric units. As a result, the spacecraft was ordered to orbit around a dangerous low latitude, causing it to burn in the Martian atmosphere.