Evaluation of the 2-Poisson model as a basis for using term frequency data in searching

Vijay V. Raghavan, Hong-pao Shi, C. T. Yu
1983 Proceedings of the 6th annual international ACM SIGIR conference on Research and development in information retrieval - SIGIR '83  
The early work on the probabilistic models of retrieval assumed 1.
doi:10.1145/511793.511806 dblp:conf/sigir/RaghavanSY83 fatcat:v7dedmgj4fbfdgiysf37kohymu