Before revision: Kirk Borne, an astrophysicist who was employed as a data scientist at NASA Goddard Space Flight Center at the time, noted in an April 2013 TED talk that he had used the phrase "unknown unknowns" in a talk to personnel at the Homeland Security Transition Planning Office a few days prior to Rumsfeld's remarks, and speculated that the term may have percolated up to Rumsfeld and other high-ranking officials in the Defense Department.
After revision: Kirk Borne, an astrophysicist who was employed as a data scientist at NASA Goddard Space Flight Center at the time, said in an April 2013 TED talk that he had used the phrase "unknown unknowns" in a talk to personnel at the Homeland Security Transition Planning Office a few days prior to Rumsfeld's remarks, and speculated that the term may have percolated up to Rumsfeld and other high-ranking officials in the Defense Department.