The topic of the seminar will be the measurement of the direct CP violation parameter ε′ ⁄ ε by the KTeV experiment at Fermilab. This measurement is based on KTeV's 1996-1997 data sample, which is approximately four times larger than that used for KTeV's first ε′ ⁄ ε result. New measurements of other parameters in the neutral kaon system also will be discussed.