Title
Analyzing the Influence of Bigrams on Retrieval Bias and Effectiveness
Abstract
Prior work on using retrievability measures in the evaluation of information retrieval (IR) systems has laid out the foundations for investigating the relationship between retrieval effectiveness and retrieval bias. While various factors influencing bias have been examined, there has been no work examining the impact of using bigram within the index on retrieval bias. Intuitively, how the documents are represented, and what terms they contain, will influence whether they are retrievable or not. In this paper, we investigate how the bias of a system changes depending on how the documents are represented using unigrams, bigrams or both. Our analysis of three different retrieval models on three TREC collections, shows that using a bigram only representation results in the lowest bias compared to unigram only representation, but at the expense of retrieval effectiveness. However, when both representations are combined it results in reducing the overall bias, as well as increasing effectiveness. These findings suggest that when configuring and indexing the collection, that the bag-of-words approach (unigrams), should be augmented with bigrams to create better and fairer retrieval systems.
Year
DOI
Venue
2020
10.1145/3409256.3409831
ICTIR '20: The 2020 ACM SIGIR International Conference on the Theory of Information Retrieval Virtual Event Norway September, 2020
DocType
ISBN
Citations 
Conference
978-1-4503-8067-6
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Abdulaziz AlQatan100.34
Leif Azzopardi21919133.10
Yashar Moshfeghi330123.60