The dictionary lookup method ("DL") unsurprisingly achieves the best precision, but the recall on Twitter is not competitive.
the Twitter normalisation cannot be tackled with dictionary lookup alone, although it is an effective preprocessing strategy when combined with more ro-   (Cook and Stevenson, 2009); MT = SMT (Aw et al., 2006); DL = dictionary lookup; WS = word similarity; CS = context support) bust techniques such as our proposed method, and effective at capturing common abbreviations such as gf "girlfriend".