BiddyBuddy: Introspective Binary Search

To get a feel for this, think of your favorite number and click the up/down buttons until you hit it.

Why? To help you pick your bid in a sealed-bid auction. It can be hard to introspect on your utility function. But it's pretty easy to see a price and say whether you're willing to pay that much or not. So that's what BiddyBuddy does. It shows you possible prices (or values or however you want to think of them) and lets you say yes or no until you've homed in on your true utility.

PRO-TIP: Start by mashing the buttons till you're in a range where you have to start introspecting harder. As soon as as you find yourself agonizing, go with the current number. If you can't decide if the Goldilocks number is too high or too low, perfect, that's exactly what it means for it to be your true utility aka your indifference point.

The Gory Details

BiddyBuddy starts with a lower and upper bound on your possible utility. It defaults to 0–999 but you can edit those however you like. Call those bounds LOW and HIGH. The Goldilocks number is always some randomly chosen number between LOW and HIGH, biased toward the middle of the range (we use a triangular distribution). When you click the down button, you're saying that the Goldilocks number is actually too high, so HIGH is replaced by the Goldilocks number and the Goldilocks number is rechosen for you. Likewise if you click the up button.

Whenever you're happy with the Goldilocks number, copy-paste it to whatever auction you may need it for.

Credits

Built by Daniel Reeves, Bethany Soule, and Christopher Moravec. See also bid.yootl.es and auction.morehavoc.com etc.