Hey everyone, I'm a marine biologist and therefore math and statistics is my nemesis haha. However, I'm currently working on GPS data of wild seals and use R to analyse it. I ran a data stratification based on recommendation, because out of 15 individual seals there are different amounts of swimming trips. So some seals have over a 100 trips while others have much fewer. I was analysing the data over all seals and trips as well and I wanted to be sure that there's no bad influence by the fact that all seals have low trip numbers, but high trip numbers (>100 e.g.) are less frequent. ChatGPT recommended to use a data stratification because it ensures that all trips and seals contribute equally to my analysis. I was also checking for some papers, but as far as I understood the whole stratification process I can't really find a paper that uses this for a similar kind of subject as me and I'd like to have some literature to cite. Maybe anyone is familiar with stratification or knows what key words I can run in Google Scholar other than data stratification in animals e.g.

Thanks and best regards