Secondary Notation
Adapted from the Cognitive Dimensions of Notations framework (Green & Petre, 1996; Blackwell & Green, 2003). See About the Dimensions for framework references.
Secondary Notation refers to extra information conveyed through means other than the formal syntax of the system — visual or textual cues that supplement the primary notation without changing its semantic meaning. Comments in code, colour tags on layers, spatial arrangement of nodes in a graph, naming conventions, and manual annotations are all forms of secondary notation.
In complex professional software, secondary notation is not an optional nicety — it is how experts maintain situational awareness across large, multi-session projects. Barbara Mirel's research describes this as "workspace seeding":1 users actively arrange their environment with markers, reminders, highlights, and spatial cues that help them remember where they are, what they've done, and what needs attention. When software does not support these practices, users resort to handwritten notes, screenshots, and external documents — lossy workarounds that break when context changes.
There are two flavours of secondary notation:
System-Provided Secondary Notation​
The system itself can provide secondary cues that help users parse complex information faster. Syntax highlighting in code editors is the classic example: keywords, strings, comments, and errors are distinguished by colour without changing the code's meaning. In professional tools, this extends to: type-based icons in scene hierarchies (mesh, light, camera, bone), colour-coded timeline tracks, status indicators on assets (locked, modified, outdated), and waveform visualisation on audio clips.
User-Applied Secondary Notation​
Users should be able to add their own annotations that the system preserves but does not interpret. A 3D animator who colour-codes bones by body region in the outliner is applying secondary notation — it aids navigation but has no semantic meaning to the software. A video editor who renames clips with a prefix system ("WIP_", "APPROVED_", "ALT_") is doing the same. Layer colours in Photoshop, marker labels on timelines, and sticky notes in whiteboard tools all serve this purpose.
The Anti-Pattern: Critical Information Only in Secondary Notation​
A dangerous pattern emerges when secondary notation becomes the only way to convey critical information. If the only way to know that a layer is locked is by its colour (and not by an explicit lock icon or interaction constraint), then users who are colour-blind, or who have customised their colour scheme, will miss it. Secondary notation should always supplement — never replace — formal system communication.
Testing​
- Can users add their own annotations, comments, or markers to elements in the workspace? Are these preserved across sessions?
- Does the system provide visual cues beyond the formal structure — colour coding, icons, status indicators, spatial formatting — that help users parse information quickly?
- Can users customise secondary notation (rename, recolour, rearrange) to match their own organisational systems?
- Check for the anti-pattern: is any critical information conveyed only through secondary notation, with no formal system equivalent?
- Evaluate whether the workspace supports "seeding" — can users arrange, highlight, and annotate their environment to maintain situational awareness across complex, multi-session projects?
Conclusion​
Good secondary notation support means giving users the tools to organise, annotate, and visually structure their work in ways the original designers could not anticipate. The system should provide useful defaults (colour coding, icons, formatting) while allowing users to layer their own meaning on top.
Check After Improvement​
- Visibility
- Role Expressiveness