The Internet Archive has a preservation copy of this work in our general collections.
The file type is
Hybrid human/computer systems promise to greatly expand the usefulness of query processing by incorporating the crowd for data gathering and other tasks. Such systems raise many database system implementation questions. Perhaps most fundamental is that the closed world assumption underlying relational query semantics does not hold in such systems. As a consequence the meaning of even simple queries can be called into question. Furthermore query progress monitoring becomes difficult due toarXiv:1202.2335v1 fatcat:rbybqcd7mvddlojkt5bcli5jxe