Independent Validation Test

sabki's picture

Hello All,

I had develop the NIR model using OPUS software with good results as below : R2val : 96%, R2cal : 97% RPD : 5 RMSECV : low.

I used 100 samples in the model and scanned 4 times each samples ( I got 400 sprectras). The samples are very homogenous with the same particles size. The lab reference data also cover the range that we want tested model (independent validation test).

When I do independent validation test (new samples) the result still not satisfied (R2<30%) so that can not used model for screening material (Ranking) :

1. What is the solution to investigation of the model?

2. Test set 20% in the model of 100 samples also good why independent validation test still not good?

Thank you so much for your assist

Kind Regards,