Embodiments of the present invention is a technique of searching for relevant nodes. This technique may include: in response to selection of a first node, displaying, as first relevant nodes, nodes having a first relevance of at least a predetermined value among nodes connected from the first node by two hops; and, in response to selection of at least one of the first relevant nodes, displaying the selected first relevant node as a second node involving the first node. This technique may further include displaying, as second relevant nodes, nodes having a second relevance of at least a predetermined value among nodes connected from the second node by two hops.