The Relation Circle suggests an alternative visual arrangement of interconnected elements, wherein the nodes of a network form a circle shape at equal distance. It actually covers various types of data structures that share the radial layout as the topmost order principle. Connections can occur between several nodes on the radial bondary as well as between nodes and locations within the area confined by the circle.
Relation circles have become popular with the visualization of large interconnected structures as they are provided through APIs of social networks and online communities. Another popular application field are thematic maps covered with items that belong to a certain category. Here, the label and description of a geographic entity is separated from the location itself.

Use a relation circle to display a list of items that are irregularly connected among each other in a node-and-edge structure. Your main objective is the amount and distribution of connections between the items. If you want to display large amounts of item on a thematic map that are assigned to one or several descriptive elements, the usage of this pattern might be useful, too.

Create a circular frame and place a display area populated with thematic items within its boundaries, if applicable. For each item in your dataset, create a node and place it on the circular shape at equal distance to its neighbors. Attach node label and descriptions, respectively. Link affiliated items through uniform connection lines: Lodes among each other and labels with represenations in the display area. Depending on the application scenario and amount of data, separate the node items and links into categories, and visually distinguish them, for instance through color coding.

Large network diagrams and themtic maps can quickly become confusing, particularly when the number of interconnections between single elements is high. Applied to networks, relation circles are useful to analyze such complex structures in terms of connectivity rather than spatial orientation. The amount and distribution of connections between items is the relevant information that needs to be visualized, while the spatial distribution or location of nodes doesn’t play a significant role. As the example on the previous page demonstrates, the display of extremely large sets with heavy interconnection among its elements in a radial structure doesn’t focus on the characteristics of single items but provides insight into the global nature of a link structure: Distinguishing brighter areas from dark “spikes”, the reader can instantly identify nodes or node areas of lower or higher connectivity.
In the context of thematic mapping, relation circles help to separate description and location of a data element, which can significantly improve the readability of maps that contain large number of items. Through the alignment of labels and descriptions on the radial frame, they allow to display two different order principles simultaneously.