underfitting of a calibration model

synonym: underfitting
https://doi.org/10.1351/goldbook.10158
Condition in which a model fails to describe the data adequately.
Note: Underfitting generally occurs when a model is not sufficiently complex, such as having too few parameters.
Example: Fluorescence intensities with excitation wavelength and emission wavelength representing the two variable axes, and the objects making the third direction.
Source:
PAC, 2016, 88, 407. (Vocabulary of concepts and terms in chemometrics (IUPAC Recommendations 2016)) on page 436 [Terms] [Paper]