Hi all! first timer here. I need to find out to what degree (in the form of a P value or r^2) some spectra are similar to each other or different. here is the problem: 1. I have 10 groups; 10 taxonomic different groups of zooplankton (small marine animals). 2. each group has between 4 and 11 replicates (I measured 4-11 individuals from each specie). 3. each replicate is a spectrum; for each replicate the spectrum is composed of a series of 600 values. 600 light intensity values corresponding to the 600 wavelengths they were measured at. the wavelength spans from 400 to 700 nm. 4. I want to know to what degree are these spectra similar to each other within the groups, and between the groups. From eyeballing them I can say that they are pretty similar within the groups in some groups and not so similar in other groups. I can also say that they look rather different from each other between the groups. but I need to know how significant it really is. what is the statistically correct thing to do? thanks in advance! -- Yakir L. Gagnon, PhD student The Vision Group Tel +46 (046) 222 93 40 Cell +46 (073) 7536354 Fax +46 (046) 222 44 25 www.student.lu.se/~kem02yga/CV www.biol.lu.se/funkmorf/vision ---------------------------------------------- CLASS-L list. Instructions: http://www.classification-society.org/csna/lists.html#class-l