There is a growing realization that conventional wisdom about pictures being "worth a thousand words" is a gross generalization when it comes to informational graphics. Rather, the interpretation of certain types of graphics can sometimes be a very demanding process indeed. In addition, it is becoming clear that graphicacy skills are largely learned rather than innate and that a viewer's capacity to interpret particular types of graphics has a great deal to do with their background knowledge. There are two main types of background knowledge that are important in comprehending graphics: