We investigate the notion of K-triviality for closed sets and continuous functions in 2N. For every K-trivial degreee d, there exists a closed set of degree d and a continuous function of degree d. Every K-trivial closed set contains a K-trivial real. There exists a K-trivial Π1 class with no computable elements. A closed set is K-trivial if and only if it is the set of zeroes of some K-trivial...