Update README.md

Author: phueb

README.md

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 # AONewsela
 
-Age-ordered Newsela
 
 A Python API for loading the Newsela corpus, 
 which consists of news articles written for children at various grade levels.
-It is loaded in "age-order"; for example, articles written for lower grades are loaded first.
+It is loaded in "age-order" (AO). 
+That is, articles are loaded in order of increasing grade-level.
+Its primary purpose in NLP, is to study how increasing langauge complexity influences language learning in artificial learning systems.
 
 This repository does not contain any language data, which is proprietary. 
 The data is loaded from a password-protected drive, and only users with access can load the data.