A tweet from Karen Bachmann led me to an article in The Boston Globe, "How facts backfire." It says:

Facts don't necessarily have the power to change our minds. In fact, quite the opposite. In a series of studies in 2005 and 2006, researchers at the University of Michigan found that when misinformed people, particularly political partisans, were exposed to corrected facts in news stories, they rarely changed their minds. In fact, they often became even more strongly set in their beliefs.

If you've ever been in the middle of a a design debate, you might recognize this effect. The more the team argues, the more everyone is convinced of their own position, so the people with control over the next step tend to win by default. Pretty discouraging to a UX-er with strong user data to back up their "opinion."

The problem isn't the ideas. It's the way you're presenting them: head on, fact vs. fact and diagram vs. diagram.

What's the solution: try a story instead. Steve Denning suggests a new persona to try if you want to persuade:

Let us call the person who converses in this mode, homo narrans -- a person who combines story-telling and analysis in a discourse that is rational, lively, imaginative, open to dialogue, entertaining and persuasive. This is the kind of person we would like to have at our dinner tables, and with whom we would be willing to discuss even the most difficult and controversial of topics. It is the sort of the person we might like to have as a friend and companion. It is the sort of person we would listen to, since conversing with homo narrans might well lead to the mutual discovery of truth.

Next time you have the facts on your side, craft them into a story. See if it doesn't work better than head-on argument.