Collins, R. A. & Cruickshank, R. H. Known knowns, known unknowns, unknown unknowns and unknown knowns in DNA barcoding: a comment on Dowton et al. Syst Biol 63, 1005 1009, https://doi.org/10.1093/sysbio/syu060 (2014).
We are in the Rumsfeldian realm of known knowns, known unknowns and unknown unknowns.
The answer is that all are fields, according to recent scientific papers, that have "known knowns", "known unknowns" and "unknown unknowns".
Rayner therefore adds a fourth category to the three coined by former US Secretary of Defense Ronald Rumsfeld ("known knowns", "known unknowns" and "unknown unknowns").
One was "There are knowns, known unknowns, and unknown unknowns". (The saying is attributed, naturally, to "Unknown"). "I think this construct is just powerful," Rumsfeld said.
One was "There are knowns, known unknowns, and unknown unknowns".
(He had high praise for Rumsfeld's categories of knowledge: known knowns, known unknowns, and unknown unknowns).
I couldn't exit my North Side polling place Tuesday without considering former Defense Secretary Donald Rumsfeld's entertaining wisdom about life presenting us known knowns, known unknowns and unknown unknowns.
Stockmann, U. et al. The knowns, known unknowns and unknowns of sequestration of soil organic carbon.
What we can say with confidence is that the answers are either known unknowns, unknown knowns or -- worst-case scenario -- unknown unknowns.
And these are, as Donald Rumsfeld would have said, the known knowns ; including the known unknowns and unknown unknowns, the figures could be higher.
