We have used Test Cells for a Marketing Campaign and from the Target Group, each Test Cell is 25% of the total size of the Group. Users would like to know who will be the recipients on each Test Cell.
NetSuite uses a number generator built into the Java which generates an approximate truly random process. Recipients will be assigned to test cells randomly.
The only way we can know which members or recipients belong to a Test Cell is to create a Saved Search using a Campaign Response : Recipient Entity filter. (See SuiteAnswers "Create a campaign response report showing statistics specifically for the test cells used on your marketing campaign" ID: 20230).
Since the recipients are selected in a random process, a Customer that belong to Test Cell A previously may belong to Test Cell B the next time an Email Marketing Campaign using Test Cells is executed.