As noted iň Stajner and Glavaš (2017), data-driven approaches outperform rule-based systems in the area of lexical simplification (Glavaš andŠtajner, 2015;Paetzold and Specia, 2016;Nisioi et al., 2017;Zhang and Lapata, 2017).
the state-of-the-art syntactic simplification approaches are rule-based (Siddharthan and Mandya, 2014;Ferrés et al., 2016;Saggion et al., 2015), providing more grammatical output and covering a wider range of syn-tactic transformation operations, however, at the cost of being very conservative, often to the extent of not making any changes at all.