Writing Experiment (Please Help!)

I'm going to have a writing experiment.

I can never decide if I'm better off writing a story with or without an outline, which is what this 'experiment' is aimed at finding out. I'm going to write one story with an outline planned, and one story with absolutely no planning whatsoever (besides basic character references and other small notes). Both will be in the same genre, posted on Mibba at the same time and day, one chapter per week.

My problem is this: how do I measure which one is better? If I go just by the amount of readers, recs, and comments left by people, it might not be very accurate of how well the story is going for various reasons (people only have time to read one, aren't interested in the plot of one, etc.).

I'm also worried about knowing when to stop. The story with the outline will planned start to finish, so knowing when to stop that one won't be an issue. But, I don't want to end up with one story at the end and the other right in the middle, which could happen since one doesn't have an outline.

When it comes to planning out experiments and using the scientific method, I have problems finding holes in the experiments and looking at things analytically. So, does anyone have any advice as to how I could remedy these issues? Additionally, can you find any other potential problems or issues I've overlooked that could possibly skewer or mess up the 'data' at the end of the experiment?

I'd really appreciate the help, everyone! This is something I really want to do just to help me figure out my writing methods, but I don't want to start doing it until I know I've worked out the majority of the kinks. Please leave a comment on this blog if you notice something wrong! Thank you!