?session marker lets you explicitly name the user sessions if you want to do everything within one Python process. However, you can also just start multiple processes on different ports and have your annotations add to separate datasets. This is often cleaner and makes it easier to compare the annotations later on.
Yes, if you don’t name the session, all annotations will be added to one default session.
This is something that Prodigy can’t decide for you – that’s something you have to decide If you trained a model with conflicting annotations, it typically ignores them, because there’s no valid gold-standard annotation that the model can learn from.
If you need to reconcile annotations from different annotators that may be conflicting, check out the new
review recipe. It lets you load in one or more datasets and will group all annotations on the same input text together. You can then see who annotated what and where the conflicts are – and create one correct “master annotation”. See here for a little video that shows the process in action: