  This paper presents a multilayered architecture that enhances the
capabilities of current QA systems and allows different types of complex
questions or queries to be processed. The answers to these questions need to be
gathered from factual information scattered throughout different documents.
Specifically, we designed a specialized layer to process the different types of
temporal questions. Complex temporal questions are first decomposed into simple
questions, according to the temporal relations expressed in the original
question. In the same way, the answers to the resulting simple questions are
recomposed, fulfilling the temporal restrictions of the original complex
question. A novel aspect of this approach resides in the decomposition which
uses a minimal quantity of resources, with the final aim of obtaining a
portable platform that is easily extensible to other languages. In this paper
we also present a methodology for evaluation of the decomposition of the
questions as well as the ability of the implemented temporal layer to perform
at a multilingual level. The temporal layer was first performed for English,
then evaluated and compared with: a) a general purpose QA system (F-measure
65.47% for QA plus English temporal layer vs. 38.01% for the general QA
system), and b) a well-known QA system. Much better results were obtained for
temporal questions with the multilayered system. This system was therefore
extended to Spanish and very good results were again obtained in the evaluation
(F-measure 40.36% for QA plus Spanish temporal layer vs. 22.94% for the general
QA system).
