NIRS LEARNING

Ana Garrido-Varo

TIPS TO START AN NIRS LEARNING PROCESS

Maybe many of you got involved in NIRS research just recently and you did not have the chance to follow any previous NIRS education. Maybe your supervisor also just started to do research on NIRS and passed on to you the responsibility of doing an MSc or PhD on NIRS without too much help. I would like to give you a few tips that I think might help to start your research. 

Tip 1. If you think that your knowledge on NIRS and chemometrics is rather limited (if not non-existent), speak with your supervisor and tell him/her that you would like to follow an intensive immersion course before to go ahead with your research. There is a range of NIRS courses. Here you a have an introductory one in English http://www.pdkprojects.com/pdkcoach.html#outline and another one in Spanish http://www.uco.es/servicios/scai/cursos/Info_Curso_NIRS_2009_10Ed.pdf.

Tip 2. Tell your supervisor that you need to read an introductory book (or more). Here you have a few: http://www.impublications.com/shop/handbook-of-near-infrared-analysis-3rd-edn-revised-and-expanded.html; http://www.impublications.com/shop/near-infrared-technology-in-the-agricultural-and-food-industries.html; http://www.impublications.com/shop/statistics-in-spectroscopy-2nd-edn.html; http://www.impublications.com/shop/a-user-friendly-guide-to-multivariate-calibration-and-classification.html.  If your supervisor can´t afford to buy these books, use the “Interlibrary books loan”. Personnel from your university library will locate and request materials from other libraries on behalf of you or your supervisor.

Tip 3. Go to Google and try to find a glossary of NIRS (or near infrared spectroscopy) terms. Here you have one http://www.spectroscopynow.com/FCKeditor/UserFiles/File/specNOW/HVS_Glossary_of_Terms.pdf. It will be of great help for the beginning of your NIRS reading. You will find definitions for terms such as noise, baseline, path length, etc.

Tip 4. Ask any question you have to other more advanced users near to you. Register in the NIRS discussion forum (http://www.nirpublications.co.uk/cgi-bin/discus/discus.cgi). Click on “Topics” and then “Bruce Campbell´s list”. You will find hundreds of questions and answers on many different topics. This is an excellent free resource for learning. Read all of it!! You can also ask your own questions (not previously asked) to the forum.

Tip 5. Discuss and agree with your supervisor on the key words to use for your review of the state of the art. That is essential for a good literature searching. Be careful NIR and NIRS produce different results!! Find a set of good papers for a general view of NIRS. Ideally you should find a couple of recent reviews. Here you have one, http://www.nearinfrared.com/nirandchemometrics.pdf.

Tip 6. I strongly recommend you to visit this page http://www.acc.umu.se/~tnkjtg/chemometrics/tutorials.html for your self-learning on chemometrics. This resource has plenty of excellent free tutorials, glossary of statistical terms, HyperStat online textbooks, and much more!

Tip 7. When reading a paper, you must think of the following: 1. You are reading it in order to know what others did previously; 2. You are reading it to get ideas for your own research, that is, what you can do in your research to go further; 3. You are reading it to comment on it in your own literature review section (what the authors did) and also in your results and discussion section. So in order to facilitate the comparison of your results with others, be sure that you know exactly for each paper several key methodological aspects which make different results using the same product/application: instrument model, scanning range, cup used, data-pre-treatment, number of samples, characteristics of the calibration and validation sets used (mean, range, standard deviation). Never discuss your statistics results for SEC, SECV or SEP, in absolute numbers! Try to standardize it with statistics as CV, RPD and/or RER.

Come on, start today with tip 1 and 2 at least!
Enjoy your NIRS learning process. I did and I am still enjoying it very much!!!

Ana Garrido-Varo
Chair-elect: ICNIRS
Chair: ICNIRS Education sub-committee