FYI just in case it's of interest and hasn't shown up on the team's radar yet: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7194368 - paywalled, unfortunately.
Quote from the abstract:
"This paper discusses expressivity and accuracy of the By-Example Structured (BESt) Query paradigm implemented on the SWiPE system through the Wikipedia interface. We define an experimental setting based on the natural language questions made available by the QALD-4 challenge, in which we compare SWiPE against Xser, a state-of-the-art Question Answering system, and plain keyword search provided by the Wikipedia Search Engine. The experiments show that SWiPE outperforms the results provided by Wikipedia, and it also performs sensibly better than Xser, obtaining an overall 85% of totally correct answers vs. 68% of Xser."
(For context, there's an earlier paper where they describe an earlier version of that SWiPE - "Search Wikipedia by example" - project: http://web.cs.ucla.edu/~zaniolo/papers/AtzoriZ12 )