Table 2. Classification of previous studies according to their methodology.
| Authors | Algorithms | Sentiment analysis | Other methodologies |
|---|---|---|---|
| Banerjee & Chua (2014) | √ | ||
| Banerjee et al. (2015) | √ | ||
| Cardoso, Silva & Almeida (2018) | √ | ||
| Chang et al. (2015) | √ | ||
| Li et al. (2014) | √ | ||
| Li, Feng & Zhang (2016) | √ | ||
| Li et al. (2018) | √ | ||
| Luca & Zervas (2016) | √ | ||
| Lappas, Sabnis & Valkanas (2016a) and Lappas, Sabnis & Valkanas (2016b) | √ | ||
| Chen, Guo & Deng (2014) | √ | ||
| Deng & Chen (2014) | √ | ||
| Elmurngi & Gherbi (2017) | √ | ||
| Lin et al. (2014) | √ | ||
| Zhang et al. (2016) | √ | ||
| Hunt (2015) | √ | ||
| Munzel (2016) | √ | ||
| Ramalingam & Chinnaiah (2018) | √ |