Table 1.

Overview of the four methods we developed and employed in our studies

Method	Online sentiment analysis	Automated topic ranking	Thematic probing	Policy landscape analysis
Aim	Understanding public attitudes towards a subject over time	Identifying main topics of online discussions	Probe the occurrence of predefined themes in online discussions	Building hypothesis on online policy documents
Related methods	Public opinion polls	Qualitative content analysis	Qualitative content analysis	Social network analysis
Technical approach	Natural language processing	Statistical big data analysis	Regular expression matching	Crawling, network analysis