  SCORE was introduced as a spectral approach to network community detection.
Since many networks have severe degree heterogeneity, the ordinary spectral
clustering (OSC) approach to community detection may perform unsatisfactorily.
SCORE alleviates the effect of degree heterogeneity by introducing a new
normalization idea in the spectral domain and makes OSC more effective. SCORE
is easy to use and computationally fast. It adapts easily to new directions and
sees an increasing interest in practice. In this paper, we review the basics of
SCORE, the adaption of SCORE to network mixed membership estimation and topic
modeling, and the application of SCORE in real data, including two datasets on
the publications of statisticians. We also review the theoretical 'ideology'
underlying SCORE. We show that in the spectral domain, SCORE converts a
simplicial cone to a simplex, and provides a simple and direct link between the
simplex and network memberships. SCORE attains an exponential rate and a sharp
phase transition in community detection, and achieves optimal rates in mixed
membership estimation and topic modeling.
