The sentence aligned data set contains two files:

normal.aligned
simple.aligned

with English Wikipedia sentences and Simple English Wikipedia sentences respectively.  The files
have the same number of lines and the nth line in one file corresponds to the nth line in the other.

The Wikipedia data was downloaded in May 2011.

The data set contains metadata about where each sentence came from.  Each line in the files are 
of the form:

article_title<TAB>paragraph_number<TAB>sentence

Additional information about the data can be found at:

http://www.cs.middlebury.edu/~dkauchak/simplification/

For questions/concerns, please contact David Kauchak at Middlebury College.

To cite, please use:
  Improving Text Simplification Language Modeling Using Unsimplified Text Data. David Kauchak (2013). In Proceedings of ACL.

or the paper for version 1 of the aligned data:
  Simple English Wikipedia: A New Simplification Task. William Coster and David Kauchak (2011). In Proceedings of ACL.
