Strategy maps positions on both an objective and subjective levels. Both facts and opinions are important because both are forms of knowledge on which people make decisions. An example of how Sun Tzu's strategy joins the objective and the subjective is the idea of "distance." While distance is a physical feature that can be measured, it is also a measure of the amount of learning required to reach a certain point. A recent article about the Wealth of Nations in Science News On-Line
actually illustrates one aspect of this intellectual distance. They call the idea "product distance" and it calculates the probability that a country will export two different types of products. In the product space network above, nodes represent products. The more closely products are linked, the more likely they are to be produced and exported by the same countries.