Working Backward

From a Wall Street Journal interview with John Irving on his latest book:

"Novels are exaggerations of life — we exaggerate the worst and the best of our experiences. . . . It [this story] is a tale of extreme dysfunction. I work that way because I begin with endings first. I build a novel as a piece of architecture from the back to the front. I need to do that because if you are going to take a long journey, which writing a novel is for me, I want to know that there is an emotional payoff at the end for the reader who will make the demands on himself to take that long journey. You might lose a little confidence in the story telling if you didn't have that ending waiting for you.

"I do this so obsessively that it can be as much as 18 months before I begin a novel. What I do is write the plotline backwards. It's often the case that the first lines I put down on paper are going to be found in the last chapter, or at least at the end of other chapters."