Navigating Diagrams
Not every dataset is a chart. A pulley system, a circuit, a family tree, a state machine — these are diagrams, where the structure comes from relationships like containment and connection. This page covers how Olli organizes diagrams into a tree. For the general navigation concepts, see Understanding the Tree.
How diagram trees differ from charts
Chart trees have a fixed structure (root, guide, data). Diagram trees are different: the levels come from the diagram's own structure. A pulley system might have an overview level, a subsystem level, a parts level, and an individual element level. The number and meaning of levels depends on the diagram.
The navigation controls are the same — Down Arrow to go deeper, Up Arrow to go broader, Left/Right Arrow to step across siblings.
Shared elements and groupings
Diagrams often have elements that belong to more than one group. A rope in a pulley system might connect two different subsystems. A wire in a circuit might link two separate modules.
When you reach a shared element, you can switch between its groupings to explore it from different perspectives. Press Up Arrow to see the available groupings. You hear something like "Grouping: System A (current)" and "Grouping: System B." Arrow sideways to pick one, then press Down Arrow to continue exploring from that grouping's viewpoint.
This is one of the key features of diagram navigation. These shared elements act as junctions that let you move between different parts of the diagram. See Understanding the Tree — Groupings for more on how this works.
Example: pulley system
The gallery includes a pulley system example. It describes three pulley systems with shared ropes and boxes.
Starting at the root, press Down Arrow to enter the first system. Arrow through its parts. When you reach a shared rope, press Up Arrow to see groupings for the other systems it connects. Arrow sideways to another system and press Down Arrow to explore from there.
The pulley case comes from Cheng (2004) and was used in a user study (Mei et al. ASSETS '25) that tested how blind users build a mental model of a structural diagram through this kind of navigation.
Next
- Dialogs — tables, filters, and other tools.
- Customizing Descriptions — changing what you hear at each item.