Factors Model 1 Model 2 Model 3 Model 4
β t β t β t β t
Demographic Gender(M=0)
School Year
Local Community
Economic Status		  .153
 .129
-.035
-.112		  5.91***
 4.98***
-1.33
-4.28***		  .085
 .080
-.029
-.084		    3.37***
   3.23**
 -1.17
- 3.37***		  .101
 .088
-.011
-.059		     4.25***
    3.78***
  -0.45
  -2.47*		  .082
 .087
-.017
-.037		    3.43***
   3.72***
 -0.75
 -1.55
Usage Time  .326 12.78***  .304  12.61***  .297  12.43***
Friends Numbers
Quality		  .057
-.319		     2.43*
-13.72***		  .058
-.285		     2.52*
-11.79***
Adults Father
Mother
S. Teacher
I. Teacher		 -.128
 .036
-.028
-.037		    -4.46***
     1.29
   -1.10
   -1.48
R2(adjusted R2)  .062(.059)  .160(.157)  .260(.257)  .277(.271)
\(\Delta\)R2  .062***  .098***  .101***  .017***