Components kept separate, in the value's unit (literature SCHEMA.md, UNCERTAINTY_CALIBRATION.md): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.
Uncertainty budget of the literature values of Ag9Ca2
Value
Unit
Printed
Reading
Method (class, basis)
Composition
Scatter
Conversion
Effective
-15.2
kJ/mol-atom
0.05
3.5 (unknown, calibrated)
3.5
-15.1
kJ/mol-atom
0.05
3.5 (unknown, calibrated)
3.5
-14.6
kJ/mol-atom
0.05
3.5 (unknown, calibrated)
3.5
-14.5
kJ/mol-atom
0.05
3.5 (unknown, calibrated)
3.5
Sources
M. Helena Braga, Adam Dębski, Władysław Gąsior, Optimization and assessment of the Ag–Ca phase diagram, Journal of Alloys and Compounds 612, 280-286 (2014). doi:10.1016/j.jallcom.2014.05.141