Table 8. Number of articles predicting political orientation, with associated predictors and references.

Category (n = no. articles)	Predictors (n = no. articles)	References
Social Media (25)	Meta-data (4)	[252,335,337,342]
	Language (24)	[19,20,299,302,335–342,62,343–346,75,82,84,252,255,274,293]
	Network Data (10)	[62,82,86,252,293,299,336,339,340,344]
	Facebook Likes (2)	[10,11]
Websites (3)	Language (3)	[62,293,351]
	Network Data (2)	[62,293]
	Location Data (1)	[293]
	Name Data (1)	[293]
Search Engines (1)	Facebook Likes (1)	[9]
Blogs (4)	Language (4)	[347–350]