Hello,

I inputted a performed experiment results in a Historical Data RSM form, and in the Fit Summary analysis "attached" all the numbers "compared to my knowledge in theory" imply that the quadratic model should be selected, but Design Expert still suggests a 2FI Model!

the Fractional design space graph though shows that the standard error of the design is somewhat lower for the 2FI? but how come that doesn't reflect in the Fit Summary results?

Can anyone please enlighten me on this issue?

Thank you very much,

A.Y.A