Feedback  loops  are kept  short  but  they are usually  of  very  little  relevance   because   they  often   over- emphasize  academic  skills.  Since  the  choice  of  the  external criteria will in the end determine what kind of applicants will be accepted, it is normal that the choice of these criteria should be made by the overall personnel policy makers. It is obvious, but not always that evident, that the chosen criteria should be quantified as a sound measurement and that such data needs to be made available to the persons in charge of the selection system quality assessment. A system should not rely on a single external criterion since none is perfect but rather it ought to consider a series of quality indicators. These should include both quality indicators independent of officer performance assessments and a representative set of indicators of the performance of the officers. Whatever the result of the quality assessment, one should always consider ways to improve the selection system. This needs to be done by trying alternatives for the different selection tools and for  the use of those tools in  the decision making process. In doing so, one has always to remember not to use a new tool in the decision making process before its quality has been proven.