Dada was a protest by a group of European artists against World War I, bourgeois society, and the conservativism of traditional thought. Its followers used non sequiturs and absurdities to create artworks and performances that ridiculed contemporary culture and traditional art forms. They also included "found" objects in sculptures and installations. Dada is a French word that translates as hobby horse, intended as a nonsensical name for a nonsensical art movement. The founders included the French artist Jean Arp and the writers Tristan Tzara and Hugo Ball. Man Ray, Max Ernst, Francis Picabia and Marcel Duchamp were also key contributors. The Dada movement evolved into Surrealism in the 1920's.