What works better for question answering: Stemming or morphological query expansion

How do different information retrieval techniques affect theperformance of document retrieval in the context of question
answering? An exploration of this question is our overall re-
search goal. In this paper, we specifically examine strategies
for coping with morphological variation. This work quanti-
tatively compares two different approaches to handling term
variation: applying a stemming algorithm at indexing time,
and performing morphological query expansion at retrieval
time. We discovered that, compared to the no-stemming
baseline, stemming results in lower recall, and morphologi-
cal expansion yields higher recall. By separately weighting
different term variants, we were able to achieve even higher
recall, which opens the door to interesting question analy-
sis algorithms for sophisticated query generation. Another
significant contribution of our work is the development of a
reusable question answering test collection to support our
experiments.