I find Palladio is very useful to to visualize networks or relationship with a map view. It is interactive so you can choose the two things between which you want to find relationship.
For example, you want to see interviewers and their topics. You choose these two items, the source is interviewer and target is topics. Then Palladio will map out a network that will show the relation between interviewers and the topics. You can also choose to highlight one or both items to make it easier to see the relationship. You can click “size nodes” to adjust the size of nodes. In short, Palladio is very interactive and user-friendly tool to show network or relationship. The downside of the tool is despite its map view, it doesn’t show geography as shown by a standard map or you can’t get information about the nodes (places, people etc) by hovering your mouse click. It strength is it can show network and relationship very well.