This chapter frames the ongoing epistemological evolution of information architecture as a shift, under the pressure of social and technological change, from the “classical” information architecture of the 1990s and early 2000s to a “contemporary” information architecture. It then establishes a differentiation between the two, modeled in accordance with the conceptualization of innovation in fields of knowledge offered by Van Gigch and Pipino’s Meta-Modeling Methodology. © 2021 The Author(s), under exclusive license to Springer Nature Switzerland AG