Speaker : Dr. Douglas Stones (Monash University)
Title : The trouble with network motifs: an analytical perspective
Time : 2013-01-18 (Fri) 15:30 - 17:00
Place : Seminar Room 617, Institute of Mathematics (NTU Campus)
Abstract: Network motifs are network sub-structures which occur with a significantly higher frequency than in randomised networks. It is thought that network motifs play a more important role than arbitrary sub-structures. Mainstream methods for discovering network motifs rely implicitly on assumptions of independence between candidates and a normal distribution of the frequency counts. We show that this is simply not true: different candidates have different distributions. Furthermore, we show that definitions which have been conflated in the literature, e.g. frequency-based vs. concentration-based statistics and high-frequency vs. low-probability motifs, can lead to diametrically opposite conclusions and, indeed, to ill-defined concepts.