# Meta-analysis for an interaction effect

Hello,

Is it possible to perform in JASP a mini meta-analysis (3-4 studies) for an interaction effect between a dichotomous and a continuous variable (tested via hierarchical regression)? The ES in this case is partial R-squared.

Thanks in advance,

Orly

## Comments

I've asked around but will do some with more emphasis now. Sorry for the tardiness

Not sure what you mean exactly by 'hierarchical regression', but the interaction between an dichotomous and a continuous variable in a meta-regression involves 4 parameters that have to be estimated (intercept, coefficients for the dichotomous and continuous predictor, and a coefficient for the interaction between the latter two). If you'd do that on 4 studies, that results in a perfect fit and no degrees of freedom left to test any hypotheses, so it's just a transformation of the data. So the short answer is: No, you can't (most certainly not with only 3 studies); unless you just want to transform your data. (Meta-regression is just like normal regression, except for known error variance.)