2.  A subtask of text simplification  Replacing words or short phrases by simpler variants in a context aware fashion  Motivation  To reach out to wider range of readers having limited vocabulary ▪ Children ▪ People with low literacy level or cognitive disability ▪ Second language learners

3.  Identification of complex words or phrases  Substitute lookup  Synonyms from thesaurus  Distributional similarity  Context-based ranking

4.  Technical Medical Language  Hypertension risk factors include obesity,...  High blood pressure risk factors include excessive weight,...  Legal Language  The Products transacted through the Service are...  The Products managed through the Service are...  Low Literacy Readers  Hitler committed terrible atrocities during the second World War  Hitler committed terrible cruelties during the second World War

5.  Knowledge-based approach  Using thesaurus, Wordnet  Hard to capture all simplification contexts  Lexical simplification as paraphrasing  Paraphrasing does not deal with complexity reduction specifically  Lexical simplification as machine translation  Requires a complex-simple parallel corpora  Wikipedia-Simple Wikipedia corpora ▪ Not comparable

6.  Simple English Wikipedia (SEW)  Edition of normal or Complex English Wikipedia (CEW) written in simpler constructs with restricted vocabulary  Wikipedia for children, low literacy readers, second language readers etc.  121,095 content pages  Semi-parallel to it’s complex counterpart Resource: For the sake of simplicity: Unsupervised extraction of lexical simplifications from Wikipedia, Yatskar et al.

7. Version 1 Version 2 Edits Version n Edits

9.  Edits in SEW versions are mix of different types of edits  The task  Separate out only simple edits from other edits

13. Probability estimation of fix edit

14. fix + simple edit

19. Resource: Putting it Simply: a Context-Aware Approach to Lexical Simplification, Biran et al. Self Study