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 Bi2FeTi4
Value
Unit
Printed
Reading
Method (class, basis)
Composition
Scatter
Conversion
Effective
-25.72
kJ/mol (basis unstated)
0.005
27.5 (dft, calibrated)
27.5
Sources
L.H. Huang, Q. Chen, Y. He, X.M. Tao, G.M. Cai, H.S. Liu et al., Thermodynamic modeling of Fe–Ti–Bi system assisted with key experiments, Calphad 46, 34-41 (2014). doi:10.1016/j.calphad.2014.01.001