2.6.2.5. Structural hole
Structural holes were first suggested by Burt, and were used in this study to identify non-redundant relationships between two parents (There are four important indicators for structural holes: (1) the effective size of the network: this indicator represents the number of non-redundant factors in Parent A's network; (2) efficiency: for Parent A, this indicator represents the ratio of effective size to actual size; (3) constraint: this demonstrates the impact of the presence of structural holes in an ego network; and (4) hierarchy: this demonstrates the extent to which constraint focuses on each parent and the community childcare doctor. Among these, the effective size of the network and constraint are very important. Structural holes can be calculated using the following path: “Network → Ego Networks → Structural holes,” with “whole network model—normal method” selected as the method. The input data should be in the form of a symmetric adjacency matrix.