"You have to be willing to subjugate your own ego for the joint common good," Singer said.

"We really feel that the Ed school has gone out of its way to help our collaboration be successful," Willett added.

Singer and Willett were so committed to partnership that when they came up for promotion, they convinced the GSE to create an additional senior position so they could gain tenure together.

"Each of them said 'unless you consider my counterpart, I won't be reviewed for tenure,'" said Christine Sanni, GSE media relations director.

Murphy said although creating an additional tenured position at the request of faculty members "never happens," Singer and Willett represented--as usual--a unique situation.

"The senior faculty thought they were the two most spectacular statisticians [in their field] in the world," Murphy said, and so the tenure review committee decided to bend the rules to accommodate the pair.

The deanship-sharing arrangement is equally unprecedented.

No one at the Educational School could remember a Harvard dean position ever being shared by two people--even two closely-connected people.