Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Two-Poisson Model

  • Giambattista Amati
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_920

Synonyms

Harter’s model; Probabilistic model of indexing

Definition

The 2-Poisson model is a mixture, that is a linear combination, of two Poisson distributions:
$$ \begin{array}{ll} \mathrm{Prob}\left(\mathrm{X}=\mathbf{tf}\right) &=\alpha\frac{\lambda^{\mathbf{tf}}{e}^{-\lambda }}{\mathbf{tf}!}\\ {}&+\left(1-\alpha \right)\frac{\mu^{\mathbf{tf}}{e}^{-\mu}}{\mathbf{tf}!}\quad \left[0\le \alpha \le 1\right] \end{array} $$
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Recommended Reading

  1. 1.
    Bookstein A, Kraft D. Operations research applied to document indexing and retrieval decisions. J ACM. 1977;24(3):418–27.zbMATHCrossRefGoogle Scholar
  2. 2.
    Bookstein A, Swanson D. Probabilistic models for automatic indexing. J Am Soc Inf Sci. 1974;25(5):312–8.CrossRefGoogle Scholar
  3. 3.
    Damerau F. An experiment in automatic indexing. Am Doc. 1965;16(4):283–9.CrossRefGoogle Scholar
  4. 4.
    Edmundson HP, Wyllys RE. Automated abstracting and indexing-survey and recommendations. Commun. ACM. 1961;4(5):226–34. Reprinted in Sharp H, editor. Readings in information retrieval. New York: Scarecrow; 1964. p. 390–412.CrossRefGoogle Scholar
  5. 5.
    Harter SP. A probabilistic approach to automatic keyword indexing. PhD thesis, Thesis No. T25146. Graduate Library, The University of Chicago; 1974.Google Scholar
  6. 6.
    Harter SP. A probabilistic approach to automatic keyword indexing. Part I: on the distribution of specialty words in a technical literature. J Am Soc Inf Sci. 1975;26(4):197–216.CrossRefGoogle Scholar
  7. 7.
    Harter SP. A probabilistic approach to automatic keyword indexing. Part II: an algorithm for probabilistic indexing. J Am Soc Inf Sci. 1975;26(5):280–9.CrossRefGoogle Scholar
  8. 8.
    Luhn HP. A statistical approach to mechanized encoding and searching of literary information. IBM J Res Dev. 1957;1(4):309–17.MathSciNetCrossRefGoogle Scholar
  9. 9.
    Maron ME. Automatic indexing: an experimental inquiry. J ACM. 1961;8(3):404–17.zbMATHCrossRefGoogle Scholar
  10. 10.
    Puri PS, Goldie CM. Poisson mixtures and quasi-infinite divisibility of distributions. J Appl Probab. 1979;16(1):138–53.MathSciNetzbMATHCrossRefGoogle Scholar
  11. 11.
    Stone D, Rubinoff B. Statistical generation of a technical vocabulary. Am Doc. 1968;19(4):411–2.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Fondazione Ugo BordoniRomeItaly

Section editors and affiliations

  • Giambattista Amati
    • 1
  1. 1.Fondazione Ugo BordoniRomeItaly