Temporal fidelity in dynamic social networks Arkadiusz Stopczynski, Piotr Sapiezynski, Alex ‘Sandy’ Pentland and Sune Lehmann Eur. Phys. J. B, 88 10 (2015) 249 Published online: 07 October 2015 DOI: 10.1140/epjb/e2015-60549-7