Document ranking for effectiveness-efficiency tradeoffs

Abstract

Aim: A large-scale document ranking system should be both effective and efficient. Here we summarize the main features of a prototype system we built for that purpose. The success of the system is demonstrated through its relative performance for the efficiency task of the TREC 2005 Terabyte Track. Method: Building a document ranking system involves two key decisions: choosing a retrieval model, and choosing a suitable index representation. The former determines the effectiveness of the system, the latter the efficiency; and each of them affects the other. The impact-based document ranking mechanism described by Anh and Moffat [2] was chosen for our system because of its balance between effe..