  It is an increasingly common practice in several natural and social sciences
to rely on network visualisations both as heuristic tools to get a first
overview of relational datasets and as a way to offer an illustration of
network analysis findings. Such practice has been around long enough to prove
that scholars find it useful to project networks on a space and to observe
their visual appearance as a proxy for their topological features. Yet this
practice remains largely based on intuition and no investigation has been
carried out on to render explicit the foundations and limits of this type of
exploration. This paper provides such analysis, by conceptually and
mathematically deconstructing the functioning of force-directed layouts and by
providing a step-by-step guidance on how to make networks readable and
interpret their visual features.
