How to properly test modifications (AKA: don't believe every MPG claim you read)

[oldbeaver]

Originally Posted by jakobnev

Your professor was

(Dammit, that was supposed to be linked but not embedded!)

No, my professor wasn´t the same as yours. However, I like him.

My professor in Physics was Oscar García, Ph.D., Scientist and International Referee.

However, I wasn´t that good student. Don´t command Entropy.

[SecondWind]

to MetroMPG: I've read and re-read your post which starts this thread. I have no training in statistics, and although I can do the "A-B-A" testing, I don't know how to tell whether differences are significant. Can you describe "statistical significance" in layman's terms? For instance, if I do 5 two-way "A" runs with an average of 59.8 MPG, and standard deviation of 1.4, then 5 "B" runs of 60.6 MPG and s.d. of 1.4, does this mean anything?