On the need for role indicators in postcoordinate retrieval systems
F. Wilfrid Lancaster · American Documentation · 1968
Abstract A summary of the findings of various evaluations of role indicators is given. In general, the results have been negative in that little real evidence for the value of these devices has been presented. The need for roles in various subject fields and in very large systems, is discussed. They can only be justified on purely economic grounds—if the added cost involved in their use is offset by substantial reduction in the amount of output screening that must be done by the end user.