1. A method for determining a location of a mobile device within an indoor area, comprising: storing, in a database, a model indicating variations in a first attribute at different points throughout the indoor area; building, using a processor, a first decision tree including a starting node, at least one intermediate node, and an output node, the starting node presenting a first question related to the first attribute, each intermediate node presenting an additional question related to the first attribute, and the output node indicating a given point within the indoor area based on answers to the first and additional questions; building, using the processor, at least a second decision tree, the second decision tree having a similar structure to the first decision tree, including second output nodes indicating points within the indoor area, the second decision tree varying from the first decision tree in that it presents different questions related to the first attribute or in that it presents questions related to a second attribute; and comparing the output node from the first decision tree and the second output nodes from the second decision tree.