## 4 Analysis and Findings
### A Multivariate Statistical Approach
Next, a hierarchical cluster analysis (using the average linkage method) of the accounts when they are represented in this four-dimensional space produced six clusters. The decision on the exact number of clusters was made using a scree-plot of Wilk's lambdas _versus_ the number of clusters. Figure 6 presents a dendrogram of the hierarchical clustering and is used as a complementary source supporting the discussion of the findings. The dendrogram describes in detail how the accounts, forming a cluster, are actually joined to form the cluster. It shows what accounts are closer (according to the similarity \begin{table}
\begin{tabular}{c|c c c} \hline \hline  & \multicolumn{2}{c}{**Twitter account A**} & \multicolumn{1}{c}{**Sum**} \\
**Twitter** & \# common followers of A and B = \(a\) & \# followers of B, but not A = \(b\) & \# followers of B = \(a+b\) \\
**account B** & \# followers of A, but not B = \(c\) & \# not followers of A or B = \(d\) & \# not followers of B = \(c+d\) \\
**Sum** & \# followers of A = \(a+c\) & \# not followers of A = \(b+d\) & Total = \(a+b+c+d\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: An example of the common distribution of followers for two Twitter accounts. measure) than others and which accounts are grouped together before others join their group at a later stage. Cluster 1 is as follows: HCoastGuard, PressParliament, Hellenicpolice, GreeceMFA, Pyrosvestiki, GGMEofficial (mainly G2C, information provision); this cluster consists of the accounts of services and administrations of public order, the parliament and the press. e-Government services originating from the three main centers of state power are included in this cluster. From the dendrogram in Figure 6, it is obvious that Hellenic Police, Fire Brigade and, later, Coast Guard are joined to form a subcluster at an early stage. GGMEofficial and GreeceMFA are also joined together. These two primary sub-clusters are joined together and with PressParliament, at the last stage, to form Cluster 1. Therefore, Cluster 1 not only groups together the accounts of the administrations of public service, the parliament and the press, but it groups them at stages. At each stage, accounts of similar orientation or purpose are joined to a common subcluster. Cluster 2 is as follows: Diavgeia, DigitalGreece, DigiPlanGR, Madcgr, Gsis_gov_gr, Govgr, HellasYAP, MinDevGR, YPEKA, OpenGovGr, StartupGreece, Yyka_gov, PrimeministGR (mainly G2C, G2B, information provision, consultation, and collaborative environments). The Prime Minister's account, the Greek government account, the account of Ministries of Health and Environment and, especially, accounts concerning the promotion of open government and digital services are included in Cluster 2. It is interesting that governmental services regarding the promotion of digital and ICT services are included. The Prime Minister's account is grouped with the Government account very early to form a subcluster. Furthermore, the HellasYAP and Opengovgr accounts are  
Figure 6: Dendrogram for the hierarchical cluster analysis of the 27 accounts. grouped together. These two sub-clusters are joined with the Ministry of Development (MinDevGr). Diavgeia and Digitalgreece, while DigiPlanGr and StartupGreece are grouped together at an early stage. Next, these sub-clusters are joined with Yuka_gov, Gsis_gov_gr and Madcgr. In the same fashion as in Cluster 1, accounts in Cluster 2 are grouped together to form the final Cluster 2 in stages where accounts of the same or similar content, orientation or intended purpose are grouped together. Cluster 3 is as follows: e_ekpaideusi, GGNeasGenias, Yp_Paideias, VisitGreecegr (mainly G2C, G2B, information provision). This cluster mainly includes accounts of services related to education and youth. E-ekpaideusi and Yp_Paideias, services concerning education, are grouped together. Furthermore, the cluster includes VisitGreecegr, which is about promoting tourism in Greece, and at an early stage, it is grouped together with GGNeasGenias, the Secretariat for youth.