I have created my first xgboost regressor. I input some self collected data, which I scale using sklearn's standardScaler. The model is trained on approximately 25,000 samples, and then tested on approximately 7000 examples, which are entirely separate from my training set.
My question is: What might be causing this? I have tried changing the parameters of the xgboost regressor, changing which factor I input, as well as trying sklearn's gradientBoostingRegressor. The result is broadly the same whatever I try, which leads me to believe that there is something I don't understand about the process I am using. I would really appreciate any advice on why this might be occurring, and what I might be able to do to rectify my problem. Thanks in advance.