Assume that there is a fixed collection O of objects and that there are m attributes of the objects. Assume that for attribute i (with 1 ≤ i ≤ m), there is a function fi that assigns a score fi(x) to each object x in O. Typically we have 0 ≤ fi(x) ≤ 1. Intuitively, fi(x) tells the extent to which object x has attribute i. For example, if attribute i represents “redness” (telling how red an object is), then a redness score fi(x) near 1 means that object x is very red and a redness score fi(x) near 0 means that object x is far from being red.
We assume that there is a scoring function (or aggregation function) F with m arguments, so that F (f1(x), …, fm(x)) gives the overall score of object i (the result of aggregating the scores of object x over all of the attributes). It is natural to assume that F is monotone, in the sense that if yi ≤ zi, for 1 ≤ i ≤ m, then F (y1, …, ym) ≤ F (z1, …, zm). Typical scoring functions are the min, which is used in fuzzy logic [2] to represent the...
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Recommended Reading
Fagin R, Lotem A, Naor M. Optimal aggregation algorithms for middleware. J Comput Syst Sci. 2003;66(4):614–56.
Zadeh LA. Fuzzy sets. Inf Control. 1969;8:338–53.
Zimmermann HJ. Fuzzy set theory. 3rd ed. Boston: Kluwer Academic Publishers; 1996.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Section Editor information
Rights and permissions
Copyright information
© 2018 Springer Science+Business Media, LLC, part of Springer Nature
About this entry
Cite this entry
Fagin, R. (2018). Score Aggregation. In: Liu, L., Özsu, M.T. (eds) Encyclopedia of Database Systems. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-8265-9_80678
Download citation
DOI: https://doi.org/10.1007/978-1-4614-8265-9_80678
Published:
Publisher Name: Springer, New York, NY
Print ISBN: 978-1-4614-8266-6
Online ISBN: 978-1-4614-8265-9
eBook Packages: Computer ScienceReference Module Computer Science and Engineering