what do you mean with continuous?

Have you calculated the effect size? Using the Z-score to interpret possible differences?

Cheers

Hi Pedro

Thanks for your answer,

By continuous I mean that the score of motivation here is comprise between -2 and +2,

Yes I have compute the effect size between time 1 and 2 and now I would like to control the baseline level of motivation and somes covariates.

The questions behind are for example : "is change in motivation between time 1 and time 2 depend from the baseline level of motivation"; or, "is change in motivation between time1 and time 2 depend from participants characteristics such as their age or physical fitness".

Thanks again,

Guillaume you can use the analysis of variance for repeated measurements with covariates, to control the influence of some external variables. Another option is to use mix model with covariates. Try both and seek the best solution for your problem. I hope this will help.

Hi Zeljko,

In the option mix model, have you in mind some article/paper which test this kind of hypothesis?

I have start to run some mixed model on R (tutorial from Bodo Winter are awesome), but for this question precisely I have some difficulties to interpret the results. Examples would be welcome to start in this way.

It’s also true that simply and RM Anova could be informative.

Big thanks

Mixed models in R are usually specified in either the nmle package or the lme4 package.

If you use the lme function in the nmle package, analysis of variance can be conducted with the Anova function in the car package.

If you use the lmer function in the lme4 package, the lmerTest function allows to use anova and rand to test the effects in the model.