Hello, how can I find out, if a userID is already available inside a DataModel? I am trying to find out if the rating data of a user is already known within a data model, that is updated periodically. If the user is not available inside the data model, I then want do treat him as an anonymous user. And: how can I give recommendations to a new, i.e. anonymous, user if I have no values for preferences. I think the API requires me to set preferences.
Best regards, Matthias
