6.5 Link Selection

Bibliographic networks can be very dense with many links. The process to remove excessive links systematically is called network pruning or link reduction.

CiteSpace provides two ways for this purpose: Pathfinder and Minimum Spanning Tree. A comparison of the pros and cons of the two methods is detailed in a 2003 publication (C. Chen & Morris, 2003). In a nutshell, Pathfinder is a theoretically better choice but it comes at a higher price.

I recommend you to start with networks without any pruning because sometimes pruning may reduce the characteristics of the natural groupings.

We are dealing with a time series of networks, i.e. sliced networks, and a merged network. When you select either Pathfinder or Minimum Spanning Tree, you will need to make another decision on whether you want to apply the pruning algorithm to all the individual sliced networks or the merged network only, or both. Since the merged network is resulted from what you do with the sliced networks, pruning sliced networks only will still lead to a merged network with reduced links. If you check both, then you will receive a merged network with the least number of links.