We report on two major surveys for metal-poor stars in the galactic halo , the HK survey , and the Hamburg/ESO survey , which have been undertaken in order to provide targets for high-resolution spectroscopy with the Subaru HDS and other large telescopes .
We compare basic properties of these two surveys and their current status , and add some historical remarks .

The candidate selection procedures of both surveys are described in detail .
We evaluate the candidate selection by comparing effective yields ( EYs ) of the survey techniques for the identification of metal-poor stars .
It is found that EY for stars below [ Fe/H ] = -2.0 in the HES can be up to \sim 80 % for stars selected by automatic classification from machine-scanned unwidened plates , whereas in the HK survey , where stars are selected by visual inspection of widened survey plates , the EY is between 11 % and 32 % , depending on whether a pre-selection based on BV photometry has been applied .

Finally , we describe techniques used for determining stellar parameters of the survey stars by means of moderate resolution follow-up spectroscopy , and additional UBV photometry .
While follow-up observations of HES stars have just been started , the HK survey has already produced a list of \sim 4700 stars with estimates of [ Fe/H ] typically precise to \pm 0.2 dex , some 1000 of which have [ Fe/H ] < -2.0 , and roughly 100 of which have [ Fe/H ] < -3.0 .