Confidence System
Purpose
The confidence system communicates the strength of the evidence underlying each value, recommendation, and calculation on WaterBalanceTools. Every calculator, dataset record, formula, and reference page is assigned one of five confidence levels.
Why Confidence Levels Matter
Pool chemistry guidance varies in its evidentiary basis. The 104°F hot tub maximum temperature has Very High confidence because it is mandated by government safety standards. A general suggestion to check phosphate levels once per month has Informational confidence because it is based on editorial synthesis rather than a specific standard. Displaying confidence levels helps users calibrate how much weight to place on a recommendation.
Five Levels
The system uses exactly five levels: Very High, High, Moderate, Limited, and Informational. These are defined in the canonical confidence dataset (data/trust/confidence.json) and applied consistently across all content types. Confidence levels are assigned during content creation and validated at build time.
Assignment Process
Confidence levels are assigned based on the source tier of the underlying evidence: Government standards → Very High; Well-established industry standards → High; Common practice with limited peer review → Moderate; Sparse or manufacturer-specific sources → Limited; Editorial synthesis or background information → Informational.
Display
Confidence levels are displayed as color-coded badges in trust panels, dataset documentation, and formula pages. Colors: Very High = dark green, High = green, Moderate = amber, Limited = orange-brown, Informational = steel blue.
Limitations of the Confidence System
Confidence levels reflect evidence quality, not calculation accuracy. A High confidence range does not mean the calculator will produce a result accurate to the displayed decimal places. See the Precision Policy for accuracy discussion. Confidence levels are reviewed annually and updated when source quality improves or degrades.