Described herein are methods and systems that identify missing interactions in incompletely known datasets represented as complex networks. One example embodiment is a method of identifying missing connections in a complex network. The example method includes accessing an electronic representation of the network. The network includes nodes and links, the nodes represent entities, and the links represent interactions between the entities. The method further includes, for each pair of nodes in the network not directly connected by a link, (i) determining a number of paths connecting the pair of nodes, where each path is a length of at least three connections spanning between the pair of nodes in the network, and (ii) calculating a prediction score for the pair of nodes based on the number of paths connecting the pair of nodes. The method further includes ranking the pairs of nodes based on the prediction scores, resulting in an ordered list of node pairs, and selecting at least a subset of the pairs of nodes based on the ordered list of node pairs. The selected pairs of nodes represent missing connections in the network.
LINK PREDICTION BASED ON 3-STEP CONNECTIVITY