I am currently working on a simple slope for mixed model. As I am interested in a two-way interaction that involves a quadratic term of X variable and a moderator, I wanted to conduct simple slopes. When I look into prior research, as interactions with cubic term is difficult to interpret, they report by examining the simple slopes of the regression lines corresponding to all possible combinations of different levels of IV or the moderator. (see Table 3 below). [![enter image description here][1]][1] [1]: https://i.sstatic.net/d9nBn.png My question is, how do I conduct simple slope analysis in R as the above table? When I use simple_slopes function, they automatically lead to simple slope test (i.e., "sstest") of either my moderator or the independent variable. I understand the table above, but am confused how to look into it. I would highly appreciate any comments regarding this question:) Thanks you in advance!