第二层除常数项外，其它的方程里的变量就是交互项

Level 1 model:

Yij = β0j + β1j*(BAKGRD3) + β2j*(BAKGRD4) + β3j*(BAKGRD6) + β4j*(BAKGRD7) + β5j*(PARSIT1) + β6j*(BULLY1) + β7j*(STAT1) + β8j*(STAT2) +β9j*(STAT3) + β10j*(STAT4) +β11j*(STAT5) + rij
(i means the ith student; j means the jth school; Yij means the mathematic achievement score of ith student in jth school; B0j represents the intercept in the jth school; B1j, β2j, …, β11j indicates the beta coefficient for corresponding level-1 variable in the jth school; rij is the random error in the jth school)

Level 2 model:

β0j = γ00 +γ01* (SCHSIT1) + γ02* (SCHSIT5) +γ03* (INSTR5) + γ04*(TAS3) + γ05*(SCHPRI3) + u0j
(B0j represents the intercept in the jth school; γ00 is the average intercept across the level-2 schools; u0j is level-2 random effects; γ01, …, γ05 represents the coefficient for corresponding level-2 variable in the jth school)

这是我的两层的模型， 导师让加interaction terms， 第二层的parameter不是每个变量的coefficient的嘛，这个interaction怎么加啊？

下边β1j*后边的那个方程加上的变量就是 BAKGRD3的交互项，其它以此类推。右下角有个mixed的按钮，按下去就可以看出最后方程两个变量的乘积。