# Poisson regression or ANOVA, repeated measures or independent?

I have been trying to figure out the best way to approach analysis of my data for a while now and I'm struggling to understand if a Poisson regression is correct and, embarrassingly, I'm not sure if my data are independent observations.

I have two data sets:

Firstly,

I have data from rows sown with 100 seeds each (n=6) with counts of seedlings recorded at different stages of seedling development (germinated, emerged etc, 6 stages). The same seeds/seedling were tracked over time. I want to know which stages have significantly different counts of seeds/seedlings. Are these independent observations as they are different outcome variables (germinated, emerged etc)? Note: each time point can only be equal to or less than the preceding time point. Should this be approached with a GLM with Poisson distribution or can it be a simple one-way ANOVA or a repeated measures ANOVA?

My second data set has data from 10 seeds per pot (n=6 pots) for two species, under 3 different treatments. There are four outcome variables (germinated, ungerminated etc) with the seeds proportioned into one of the four outcome variables (if 80% germinate, for example, then 10% could be ungerminated and 10% dead). This means quite a lot of 0's in some cases. I have performed a Poisson regression in R to find significant differences between treatments for each outcome variable and it makes sense but I want to check that this is the best approach and meets the correct assumptions but, I'm confused..

• I'm not sure if I replied in the right section or not (I replied to the below answer rather than my question?). Is there any more information I can give that might help anyone in answering my above question? Commented Jan 16, 2021 at 0:15

Your research question for the first study needs to be stated more carefully: "I want to know which time points are significantly different (i.e. significantly less than the preceding time point).". I suspect what you really mean is that you want to know whether the expected/average value of your count outcome variable at time point $$t$$ is less than that at time point $$t-1$$? (It's clear that the time points themselves are different from each other by virtue of how you chose them.)