1st button = Like the LEFT person very much more
2nd button = Like the LEFT person much more
3rd button = Like the LEFT person more
4th button = Like the LEFT person slightly more
5th button = Like both people EQUALLY
6th button = Like the RIGHT person slightly more
7th button = Like the RIGHT person more
8th button = Like the RIGHT person much more
9th button = Like the RIGHT person very much more
So, the more you like the person on the Right, compared to the one on the left, the farther your mark will be to the right. If you would like or dislike them equally, you should click in the middle of the scale. If you like the left one better, your click will be left of the middle, and the more you like the left better, the farther to the left your mark should be.
Remember, in this task, each adjective describes a DIFFERENT person and you rate the DIFFERENCE in liking between the two.