The next steps in the study of missing individuals in networks: a comment on Smith et al. (2017)

Social network analysis is now used widely to study social behaviour in humans and non-human animals, and missing individuals can represent a problem for network studies. This problem is becoming especially frequent in studies using bio-logging to collect interaction data, which is an approach used particularly frequently in the construction of animal networks. This therefore represents an important audience for Smith et al. (2017) who investigate how sub-sampling from networks impacts the outcome of subsequent analysis. Here I take advantage of the progress made by this paper to outline key issues that still require addressing to understand the effect of missing individuals on social network analysis.