Same process different results
What could be the reason for different users obtaining completely different results (e.g. classification matrix) even though they use the exact same process, same algorithms and the parameters are exactly the same?
Also, I have noticed, I ran an estimation model with linear regression, got rmse; then I added a new model to the same process (used the Multiply operator; didn't change any parameters), and once I ran the process with two models, the rmse of the linear regression has changed. What might be the reason for that?