INCCA loosely defines modern art as artistic works from the late 19th century though the 1960s. Modern art is often experimental and frequently abstract. Contemporary art is considered to have begun in the 1960s, as artists challenged the concerns of modern artists and questioned the definition of art itself. Given the complex nature of artistic movements during this period, INCCA adopts broad definitions of these terms and relies on its members to decide what, for instance, qualifies as appropriate art for its Database.