Decision trees are widely used method to codify explicit knowledge. The decision tree is typically in the form of a flowchart, with alternative paths indicating the impact of different decisions being made at that juncture point. A decision tree can represent many "rules," and when you execute the logic by following a path down it, you are effectively bypassing rules that are not relevant to the case in hand. Their graphical nature makes them very easy to understand, and they are obviously very well suited for the coding of process knowledge (Dalkir, 2005, p.98).

The following videoclips give some views about decision trees: