Hi, the short answer is: centering the continous IV or not does not impact the p-value of the interaction item. However, it might change other items,namely the non-interaction items (or, main effect items). You need to be careful how to interpret the meanings of the non-interaction items (i.e., main effect items). You can experiment a bit by yourself, to compare the outputs between centering and non-centering, to see the differences. I might make a separate tutorial on that in the future if I get time.
Change contrast coding (-1 and 1) into dummy coding (0 and 1), if you want to know the slope of the plot line. For more, refer to this paper: journals.sagepub.com/doi/abs/10.1509/jmr.12.0420 Further, I have a tutorial here about the difference between dummy coding and contrast coding. Note that, this video does not have interaction item. ruclips.net/video/9tBLXJjZPZs/видео.html
hi, I just made a video to answer your question, and let me know if you still have questions after watching it: ruclips.net/video/oiKa-72c_6w/видео.html
Great tutorial! Thanks for sharing!!!
Great tutorial, thank you!
Great explanation! Thanks.
do you suggest that we mean-center the continuous variable? By the way, thank you for the video. I used it to build one plot for my paper. Thank you.
Hi, the short answer is: centering the continous IV or not does not impact the p-value of the interaction item. However, it might change other items,namely the non-interaction items (or, main effect items). You need to be careful how to interpret the meanings of the non-interaction items (i.e., main effect items). You can experiment a bit by yourself, to compare the outputs between centering and non-centering, to see the differences. I might make a separate tutorial on that in the future if I get time.
What if we use -1 and 1 contrast coding instead of 0-1 coding
Change contrast coding (-1 and 1) into dummy coding (0 and 1), if you want to know the slope of the plot line. For more, refer to this paper: journals.sagepub.com/doi/abs/10.1509/jmr.12.0420
Further, I have a tutorial here about the difference between dummy coding and contrast coding. Note that, this video does not have interaction item.
ruclips.net/video/9tBLXJjZPZs/видео.html
🥺There's a question, What if both the X and M are continuous?
Let me think about that for a bit. I will reply you in a few days.
hi, I just made a video to answer your question, and let me know if you still have questions after watching it: ruclips.net/video/oiKa-72c_6w/видео.html