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 Ag9Se
Value
Unit
Printed
Reading
Method (class, basis)
Composition
Scatter
Conversion
Effective
149.37
kJ/mol-atom
0.005
9.966 (dft, calibrated)
9.966
149.37
kJ/mol-atom
0.005
9.966 (dft, calibrated)
9.966
150.532
kJ/mol-atom
5.000e-4
9.966 (dft, calibrated)
9.966
150.532
kJ/mol-atom
5.000e-4
9.966 (dft, calibrated)
9.966
Sources
Zhi Li, Shun-Li Shang, Jianyun Shen, Po-Hsien Liao, Zi-Kui Liu, Timothy J. Anderson, Thermodynamic Assessment of the Ag-Se System Aided by First-Principles Calculations, J. Phase Equilib. Diffus. 39, 870-881 (2018). doi:10.1007/s11669-018-0683-7