An excellent interview with Richard Ford on the BBC World Service World Book Club, Ford's succinct description on the potency of dialogue in fiction was worth noting:
Dialogues are doing a lot of very complex things at the same time. They are trying to seem true to the person who is saying them. They are load bearing, they're carrying lots of information, they are at the same time utterly unpredictable from one phrase to the next which is pretty much the way most of our dialogue is in life (pretty unpredictable and seem spontaneous), and they also have, as far as I'm concerned, to be funny ... I guess that little menu of things that they have to perform means that I work at them pretty hard ... I almost never write a dialogue or a couple of pages full of dialogue without going over it and over it and over it and over it, trying to be sure that it is satisfying all those ends at once.