The necessity of localizing at a prime suggested to Browder that there should be a variant of "K"-theory with finite coefficients. He introduced "K"-theory groups "K""n"("R"; Z/Z) which were Z/Z-vector spaces, and he found an analog of the Bott element in topological "K"-theory. Soule used this theory to construct "étale Chern classes", an analog of topological Chern classes which took elements of algebraic "K"-theory to classes in étale cohomology. Unlike algebraic "K"-theory, étale cohomology is highly computable, so étale Chern classes provided an effective tool for detecting the existence of elements in "K"-theory. William G. Dwyer and Eric Friedlander then invented an analog of "K"-theory for the étale topology called étale "K"-theory. For varieties defined over the complex numbers, étale "K"-theory is isomorphic to topological "K"-theory. Moreover, étale "K"-theory admitted a spectral sequence similar to the one conjectured by Quillen. Thomason proved around 1980 that after inverting the Bott element, algebraic "K"-theory with finite coefficients became isomorphic to étale "K"-theory.