  On 1 August 2009, the global Collaboratory for the Study of Earthquake
Predictability (CSEP) launched a prospective and comparative earthquake
predictability experiment in Italy. The goal of the CSEP-Italy experiment is to
test earthquake occurrence hypotheses that have been formalized as
probabilistic earthquake forecasts over temporal scales that range from days to
years. In the first round of forecast submissions, members of the CSEP-Italy
Working Group presented eighteen five-year and ten-year earthquake forecasts to
the European CSEP Testing Center at ETH Zurich. We considered the twelve
time-independent earthquake forecasts among this set and evaluated them with
respect to past seismicity data from two Italian earthquake catalogs. In this
article, we present the results of tests that measure the consistency of the
forecasts with the past observations. Besides being an evaluation of the
submitted time-independent forecasts, this exercise provided insight into a
number of important issues in predictability experiments with regard to the
specification of the forecasts, the performance of the tests, and the trade-off
between the robustness of results and experiment duration. We conclude with
suggestions for the future design of earthquake predictability experiments.
