Ethnobiology is not just a matter of matching up scientific labels to the local language names but also of understanding what features of the plant or animal people attend to in classifying them as they do. These may be quite different from what scientists emphasize. From these categories, the ethnoscientist moves on to understanding the cultural rules for using them---recognizing what reeds and palm woods are useful for making arrows of specific types for hunting birds, mammals, or other game, for example. Ultimately the ethnoscientist seeks to understand how people make complex decisions such as where to clear a field and when to plant, weed, and harvest.