Table 16. Number of articles predicting education level, with associated predictors and references.

Category (n = no. articles)	Predictors (n = no. articles)	References
Social Media (8)	Language (7)	[20,62,84,253,254,358,363]
	Network Data (2)	[62,358]
	Meta-data (2)	[358,363]
	Facebook Likes (1)	[363]
	Check-ins (1)	[170]
Websites (4)	Language (1)	[62]
	Network Data (1)	[62]
	Website Data (1)	[197]
	Meta-data (1)	[197]
	Web Browsing Histories (1)	[294]
	NR (1)	[200]
Email (4)	Language (4)	[238–241]
Wi-Fi (1)	Wi-Fi Traffic (1)	[250]