A method for estimating a value of a kerogen property in a subsurface formation where the value of the kerogen property is unknown. The method includes: measuring spectral intensity values over an infrared (IR) spectral range for a selected sample from the subsurface formation; determining a range of values representing the measured spectral intensity values corresponding to a vibrational mode attributable to kerogen in the selected sample, the range of values including values representing uncertainty in the measured spectral intensity over the portion of the spectral range; and inputting values from the range of values into a stochastic or simple regression model to determine an estimated value of the kerogen property in the selected sample.