Add reading instructions to survival curves for novice readers
For ordered-time risk displays, use text annotation on survival curves to improve readability and mitigate misinterpretation for readers with little or no experience with the graph.
- purpose:refine
- basis:empirical
- time:ordered-time
- chart:line
- lever:text-annotation
- component:annotation:use
- literacy:novice
- quality:readability
advice
Instructions on survival curves
Add a short explanation of how to read the survival curve before asking novice readers to use it. For example, place instructions beside the curve that tell readers what the line shows over time and how to interpret the display when comparing outcomes.
reason
Why instruction text helps on unfamiliar curves
Survival curves require a reading procedure that many novice readers do not already have. Short instructions give them that procedure before they try to interpret the lines.
Mechanism: Instruction text reduces uncertainty about how to use the graph and helps readers map the curve to the outcome over time.
Evidence: The paper states that instructions were instrumental to the interpretation of survival graphs among people who had little or no experience with them (Lipkus, 2007).
context
Use when readers are inexperienced with survival curves
- User Goal: Understand change in survival over time or compare options.
- Task: Read a survival curve correctly.
- Data: Survival values across time.
- Chart Setting: A survival curve shown to readers with little or no prior experience using that graph.
- Audience: Patients or other novice readers.
- Success Criterion: Readers can explain and interpret the graph correctly.
exceptions
Do not use as a special intervention for experienced readers
Break it when: Readers already have experience with survival curves. Why: The cited benefit was shown for readers who had little or no experience with them.
costs
Tradeoffs of adding instruction text
Sacrifice: You use chart space for reading guidance.
Risk: The added text can crowd a small figure.
Mitigation: Keep the instructions short and place them adjacent to the curve.
mistakes
Common failure mode on survival curves
Mistake: Presenting a survival curve to novice readers without any instructions. Why it fails: Inexperienced readers may not know how to interpret the display.
check
How to test whether the instructions are needed
Failure Sign: A novice reader hesitates or misstates what the curve is showing.
Quick Check: Ask a novice reviewer to explain how to read the curve before comparing options.
Stronger Test: Compare interpretation accuracy with and without the instruction text.
fix
What to change
- Add a short note explaining how to read the survival curve.
- Place the note next to the graphic rather than away from it.
- If the curve is still hard to use, add a more detailed verbal description when presenting it.