How baseline-relative measurement works

FCE measures change relative to an individual’s own baseline. This diagram shows the principle in simplified form.

Earlier Repeated baseline measurements
Normal range band (derived from baseline)
Later Single later measurement
Baseline
Your normal range
Normal range
Expected variability
Later check
Compared to baseline

In a baseline-relative system, measurements are interpreted by comparison to a person’s own established range, rather than to population averages.

Single measurements are not decisive on their own. Interpretation depends on context and history.

Variability and recovery

Short-term variability is a normal part of human performance. Single measurements may fluctuate due to context, attention, fatigue, or other temporary factors.

In baseline-relative systems, interpretation focuses on patterns over time rather than isolated points. How performance returns toward baseline across repeated checks can be more informative than a single deviation.

This does not explain why performance changes. It only describes how change is interpreted within a baseline-relative framework.