Unknowns exist in a spectrum, or more accurately, a 2-by-2 matrix. It’s described in a thirteenth-century poem written by Persian poet Ibn Yamin, which reads: One who knows and knows that he knows ...

“Known knowns” and “unknown knowns” are common terms in the intelligence world as well as in project management and strategic-planning circles. A known known is a fact you are aware of. A known ...

DELHI — An opening reception for “Unknown Knowns,” an exhibit of paintings and drawings by Doug Henders and Trevor Wilson, will be held from 4 to 7 p.m. Saturday, May 24, at Bushel at 106 Main St. in ...