  Data physicalizations "map data to physical form," yet many canonical
examples are not based on data sets. To address this contradiction, I argue
that the practice of physicalization forces us to rethink traditional notions
of data. This paper proposes a conceptual framework to examine how
physicalizations relate to data. This paper develops a two-dimensional
conceptual space for comparing different perspectives on data used in
physicalization, drawing from design theory and critical data studies
literature. One axis distinguishes between epistemological and ontological
perspectives, focusing on the relationship between data and the mind. The
second axis distinguishes how data relate to the world, differentiating between
representational and relational perspectives. To clarify the aesthetic and
conceptual implications of these different perspectives, the paper discusses
examples of data physicalization for each quadrant of the continuous space. It
further uses the framework to examine the explicit and implicit assumptions
about data in physicalization literature. As a theoretical paper, it encourages
practitioners to think about how data relate to the manifestations and the
phenomena they try to capture. It invites exploration of the relationship
between data and the world as a generative source of creative tension.
