Table 3.
Network-level characteristics of the Facebook friendship network at baseline and 12-months.
| Characteristic | Baseline | 12-months |
|---|---|---|
| Edge count | 3,893 | 5,207 |
| Mean (SD) Facebook friendships | 22.90 (19.53) | 30.63 (25.39) |
| Network density | 0.07 | 0.09 |
| Transitivity (network closure) | 0.26 | 0.31 |
| Centralization (network concentration) | 0.17 | 0.25 |
| Period 1 | ||
| Number of new Facebook friendship ties | 2,148 | |
| Number of Facebook friendship ties maintained | 3,059 | |
| Number of dissolved Facebook friendship ties | 834 | |
| Jaccard Indexa | 0.51 | |
a
The Jaccard index measures the amount of change between observed waves, and indicates whether the data collection points are not too far apart. Values between 0.3 – 0.6 are desired to meet assumptions that the network change process is gradual (Snijders et al., 2010).