“…There are a number of different clustering techniques available, including partitioning techniques (e.g., k-means), modelbased techniques (e.g., SOMs), hierarchical techniques (e.g., Ward's method), density-based and grid-based techniques (Han and Kamber, 2001;Wu et al, 2008;Cavélius, 2011). In this study, we adopt the SOM for the following reasons: 1) the SOM is a very visual and managerially-oriented method for the analysis of multidimensional data (Eklund et al, 2008;Länsiluoto and Eklund, 2008), 2) compared to many multidimensional visualization methods (e.g., Multidimensional Scaling, MDS), the SOM is unique in performing both projection and clustering (Vesanto, 1999;Sarlin, 2012), 3) as opposed to many traditional statistical clustering methods (such as k-means), an SOM does not require the user to specify the number of clusters beforehand, making it an ideal tool for exploratory data analysis (Wang, 2001;Wu et al, 2008), and finally, 4) an SOM is very tolerant of most forms of problematic data, including linear and non-linear relationships, skewed distributions, and erroneous or missing data (Bishop, 1995;Kohonen, 2001;Wang, 2001).…”