Connection is a visual grouping principle: elements with connected forms are perceived as correlated and belonging together. Because the connection supplies a direct visual link, the brain does not have to make a large inferential leap. section 2.2.5
Line charts
A line chart demonstrates connection by joining data points with a line. When two categories are plotted, each category should receive its own line rather than being connected across categories; otherwise, unrelated values may appear grouped. section 2.2.5
Connection belongs to a family of Gestalt grouping principles. It relates especially closely to closure and continuity: viewers can mentally complete gaps in connected or aligned forms, making separate elements read as a coherent group. section 2.2.5 section 2.3
Apply connection deliberately:
- Connect elements when their correlation or group membership should be immediately apparent. section 2.2.5
- Keep unrelated categories visually separate, especially in line-based data displays. section 2.2.5
