# Bayesian contrasts

Hi,

Is it still possible to do Bayesian polynomial contrasts in your program using the following transformation?

The goal is to check the cubic contrast for 7 levels.

In this case, the cubic contrast is -1 1 1 0 -1 -1 1.

Can I

*multiply Level1 by -1 Level2 by 1, Level 3 by 1 and so on…

*Then add level 1,2 &3 to a new variable, for example, var 1

*Then add levels 5,6 &7 to a new variable, for example, var 2 (absolute values)

*In the next step, can I use a T test to check the differences between the two means

and then look at the Bayesian value to give me an indication if there is or isn’t a cubic trend?

## Comments

Hi Shem,

I think this is possible to do with the "compute columns" functionality. There is an informative blogpost here: https://jasp-stats.org/2018/12/18/how-to-compute-columns-in-jasp/

This will probably not correct your p-values for multiple comparisons, although you can always apply Bonferroni since that's very straightforward.

Cheers,

Johnny