Dear R Community, I first apoligize to ask statistical questions of general domain, probably beyond the mere use of R. I want to analyze the following type of data with R . Total annual fisheries landings have been reported during 1950-2007 from a given fishery area. I am dealing with annual fisheries landings proportions (LP) estimated for trophic level (TL) classes of 0.1increment, i.e. each LP cell shows an estimated proportion of all fish landed for a given decade (D) year (Y) and TL class combination (usually TL = 2-5). I have observed that 0 <= LP < 1. I am interested in testing the effects for factors D, Y, TL and for interactions TL:Y and TL:D with a view to particularly verify whether PL changed over time. I am seeking for your wise experience about the following questions: 1. Which type of probabilistic distribution am I facing? Is it normal, poisson, binomial or multinomial ? 2. What would be the most appropriate R-based approach/model to handle such a study case? Thanks in advance. Joseph [[alternative HTML version deleted]]