Paper Info
Title
On Suspicious Coincidences and Pointwise Mutual Information
Abstract
Barlow (1985) hypothesized that the co-occurrence of two events A and B is “suspicious” if P(A,B)≫P(A)P(B). We first review classical measures of association for 2 × 2 contingency tables, including Yule's Y (Yule, 1912), which depends only on the odds ratio λ and is independent of the marginal probabilities of the table. We then discuss the mutual information (MI) and pointwise mutual information (PMI), which depend on the ratio P(A,B)/P(A)P(B), as measures of association. We show that once the effect of the marginals is removed, MI and PMI behave similarly to Y as functions of λ. The pointwise mutual information is used extensively in some research communities for flagging suspicious coincidences. We discuss the pros and cons of using it in this way, bearing in mind the sensitivity of the PMI to the marginals, with increased scores for sparser events.
Year
DOI
Venue
2022
10.1162/neco_a_01533
Neural Computation
DocType
Volume
Issue
Journal
34
10
ISSN
Citations 
PageRank 
0899-7667
0
0.34
References 
Authors
0
1
Name
Order
Citations
PageRank
Christopher K. I. Williams16807631.16