I am putting together a test plan for usability testing using paper prototypes of our mobile text message system. I keep getting the request to inquire about the frequency and number of text messages that we are proposing to send. Now, I know you can't ask users how many texts is too much or too little or show them our proposed schedule and ask if it looks OK because it is out -of -context.
My question is how do you test if the frequency and number of text messages sent is OK, too much, or too little when conducting cognitive interviewing or during paper prototype testing?
My gut tells me we won't be able to test that until the 12 week trial where the system is live and integrated into users' lives. But I am hoping to be proven wrong.