I recently imported a survey that I created on Qualtrics. The survey was 30 minutes long so some people stopped halfway through or at the beginning etc.. I gave each question a point value to make the survey like a test and assign grades. But when I look at final points, this includes users who chose to terminate the survey early and do not have responses from that point forward. How do I exclude them from my analysis? I know this is confusing but I'd be happy to clarify.