We have put here a few pointers to papers and tutorials that provide some technical background to PeARS. A short system description was published at WWW2016 and is available here.
University of Trento, Center for Mind/Brain Sciences
We have done a first evaluation of the accuracy of the system, which was published at the *SEM conference and is downloadable here.
University of Trento, Center for Mind/Brain Sciences
DFG Collaborative Research Centre 991 Heinrich-Heine Universität, Düsseldorf
PeARS is powered by a technique called distributional semantics. A very simple introduction to distributional semantics is available here
University of Trento, Center for Mind/Brain Sciences
If you are interested in a more technical and comprehensive introduction, check out the papers by Turney and Pantel (2010) or Clark (2012).
National Research Council Canada
University of Cambridge, Computer Laboratory
If you are hooked... have a look at this rather long bibliography,
University of Trento, Center for Mind/Brain Sciences
with many papers covering topics from formal meaning representations to multimodal semantics.