ROUGE-L Score

• ROGUE = Recall-Oriented Understudy for Gisting Evaluation
• As ROGUE compare with the ALL target sentences, it is often compared with Recall
• Better at comparing semantic meaning than ROUGE-N Score
• Heavily used in Text Summarization, Also usually used in Machine Translation with BLEU Score

[!def] ROGUE-L Score
$$
\text{ROGUE-L} = \frac{\text{Length of ALL LCS (same size) on both generation and reference}}{\text{# of words in reference}}
$$

Problems with ROGUE Score

1. Hard to compare with different tokenizers
2. Doesn't consider synonyms