In the following months, multivariate calibration models using the NIR spectral features and publication date reported in the books will be developed to evaluate the influence of sample size and sampling method on the uncertainty of the paper dating models based on NIR spectroscopy.
NIR spectroscopy followed by multivariate data analysis has been previously applied to date heritage materials, such as paper, parchment and photographs, with different accuracies of the resulted models. The sources of these different accuracies have not yet been systematically investigated, which is what UNCERTIR is addressing.