JASP and inverted-U polynomial contrasts?

Da5Ax

Hello everyone 👋😊

I am trying to use polynomial (quadratic) contrasts to find if my data follow an inverted U-shaped distribution using JASP. However, every paper I find on quadratic contrasts gives the coefficient used to find a U shaped distribution, and nothing on inverted-Us. I tried using a customized contrast, but it only gives an error message.

Does anyone know if JASP automatically tests for invterted-U shapes in the quadratic contrast ?

Thank you!

EJ

I do not immediately see how a quadratic contrast would be set up to find a U but not an inverted U. You could try generating data according to an inverted U (or take U-shaped data and transform it to give an inverted U shape), apply the software, and see whether you recover what you put in.

Cheers,

E.J.

Da5Ax

I played around by creating data and indeed, it does work, thank you!