what data is needed to do cross validation in a sandbox what is the purpose of using user data to perform cross validation can i mix and match data during cross validation which data is needed to perform cross validation can you test multiple users can data be mixed and tested to perform cross validation can you test and train from different data sets what is training and test data how to combine user data for cross validation why do you need to mix data can you split user data can i cross validate multiple users for testing can you use multiple users for testing and testing randomized data cross validation can cross validation data be randomized can i mix data for cross validation when is it necessary to mix data for cross validation how to run randomized cross validation combining test and training data when you mix data for cross validation