Table 4:
Changes in brokerage and central positions from Wave 1 (baseline) to Wave 2
| Network Statistics | Changes over first year (Wave 2 mimis Wave 1) | |||||
|---|---|---|---|---|---|---|
| Role | Prior History | Centers | ||||
|
| ||||||
| Non-PI | PI | Prior Experience | No Prior Experience | Research Centers | Analytic/Coordinating | |
|
| ||||||
| Brokerage Roles (Center- based) | ||||||
| Coordinator | 0.30 (6.68) | −1.56 (15.51) | −4.03 (14.01) | 1.08+ (7.89) | −0.60 (6.17) | 0.93 (17.42) |
| Itinerant Broker | −0.19 (1.39) | 0.33 (3.51) | −0.38 (3.30) | 0.08 (1.70) | −0.15 (2.37) | 0.30 (1.62) |
| Representative | 11.58* (36.32) | 27.64*** (53.81) | 18.62* (46.75) | 15.38*** (41.18) | 8.39* (28.07) | 40.97** (65.86) |
| Gatekeeper | 7.93 (24.29) | 26.31*** (55.85) | 20.53** (51.95) | 10.71* (30.18) | 6.86 (30.89) | 33.37** (47.00) |
| Liaison | 7.45 (29.28) | 98.81 (180.40) | 69.72 (177.33) | 21.39 (65.78) | 25.07 (81.46) | 61.27 (163.46) |
| Centrality | ||||||
| Indegree (Ties Received) | 2.18 (3.50) | 6.03 (4.99) | 2.97 (3.58) | 3.40 (4.58) | 2.46 (3.69) | 5.90 (5.18) |
| Outdegree (Ties Sent) | 2.60 (6.16) | 5.00 (10.99) | 3.81 (7.90) | 3.11 (7.92) | 2.02 (6.99) | 7.30+ (9.27) |
| Betweenness | −0.00 (0.01) | −0.01 (0.02) | −0.01 (0.02) | −0.00 (0.01) | −0.00 (0.01) | −0.00 (0.01) |
| Closeness | 0.01 (0.15) | 0.01 (0.20) | 0.03 (0.10) | −0.00 (0.18) | −0.00 (0.17) | 0.04 (0.12) |
Note:
***
p< 0.001;
**
p< 0.01;
*
p< 0.05;
+
p< 0.10; difference between Wave 1 and Wave 2 tested using permutation test. Betweenness Centrality scores are normalized. For Coordinator, Itinerant Broker, Representative, Gatekeeper, and Liaison the average frequencies are shown. Degree, Closeness, and Betweenness Centralities are continuous measures hence mean values are shown.