These methods undergo labor-intensive feature engineering and hence lead to the growing popularity of adopting data-driven neural networks.
for social media keyphrase prediction, most efforts are based on sequence tagging style extraction (Zhang et al., 2016, 2018) or classification from a predefined candidate list (Gong and Zhang, 2016; Zhang et al., 2017), which are however unable to produce keyphrases absent in the post or the fixed list