Fig. 2.

Distributions of items means in three (a) and five (b) latent class models in the whole sample. Item 1: I have difficulties for focusing on my academic work due to my online social networking use; Item 2: The first thing on my mind when I get up is to log into online social networking; Item 3: I lose sleep over spending more time on online social networking; Item 4: My online social networking use interferes with doing social activities; Item 5: I log into online social networking to make myself feel better when I am down; Item 6: My family or friends think that I spend too much time on online social networking; Item 7: I feel anxious if I cannot access to online social networking; Item 8: I have attempted to spend less time on online social networking but have not succeeded