I never asked the students in my study whether or not they procrastinated. But I did ask them if they felt they'd spent "enough time" on their papers.
See, 80% of procrastinators said they'd spent enough time, while 93% of non-procrastinators said they had. That makes sense, right? If you procrastinated, you're less likely to think you'd spent enough time on your paper. Except that the 93% of non-procrastinators is misleading. Of that 93%, several gave responses on the followup question that contradicted their answer on the "enough time" question. Only 83% of non-procrastinators gave an unequivocal "Yes, I spent enough time on my paper." And that's not out of line with the 80% of procrastinators.
And remember, all we're saying here is that non-procrastinators were more likely than procrastinators to say they'd spent enough time. The large majority of procrastinators still felt they'd spent enough time on their papers.
Here's the cool part. Since there were only five procrastinators in my study, that 20% who said "no" is only one person. This person reported starting to plan 21 days before the paper was due, the maximum of any procrastinator. And she started to draft 3 days before the paper was due. Also the maximum of any procrastinator. So the procrastinator who reported starting on her paper the earliest is also the only procrastinator who doesn't think she spent enough time on her paper.