  Matrix visualizations are a useful tool to provide a general overview of a
graph's structure. For multivariate graphs, a remaining challenge is to cope
with the attributes that are associated with nodes and edges. Addressing this
challenge, we propose responsive matrix cells as a focus+context approach for
embedding additional interactive views into a matrix. Responsive matrix cells
are local zoomable regions of interest that provide auxiliary data exploration
and editing facilities for multivariate graphs. They behave responsively by
adapting their visual contents to the cell location, the available display
space, and the user task. Responsive matrix cells enable users to reveal
details about the graph, compare node and edge attributes, and edit data values
directly in a matrix without resorting to external views or tools. We report
the general design considerations for responsive matrix cells covering the
visual and interactive means necessary to support a seamless data exploration
and editing. Responsive matrix cells have been implemented in a web-based
prototype based on which we demonstrate the utility of our approach. We
describe a walk-through for the use case of analyzing a graph of soccer players
and report on insights from a preliminary user feedback session.
