Diversity Index

A diversity index is a quantitative measure that reflects how many different types (such as species) there are in a dataset, and simultaneously takes into account how evenly the basic entities (such as individuals) are distributed among those types. The value of a diversity index increases both when the number of types increases and when evenness increases. For a given number of types, the value of a diversity index is maximized when all types are equally abundant.

When diversity indices are used in ecology, the types of interest are usually species, but they can also be other categories, such as genera, families, functional types or haplotypes. The entities of interest are usually individual plants or animals, and the measure of abundance can be, for example, number of individuals, biomass or coverage. In demography, the entities of interest can be people, and the types of interest various demographic groups. In information science, the entities can be characters and the types the different letters of the alphabet. The most commonly used diversity indices are simple transformations of the effective number of types (also known as 'true diversity'), but each diversity index can also be interpreted in its own right as a measure corresponding to some real phenomenon (but a different one for each diversity index).

Read more about Diversity IndexTrue Diversity (The Effective Number of Types), Richness, Shannon Index, Simpson Index, Inverse Simpson Index, Gini-Simpson Index, Berger-Parker Index, Rényi Entropy

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Prometheus Radio Project V. FCC - Third Circuit of Appeals (main Case) - Dissent By Judge Scirica - I. Diversity Index and Cross-media Limits
... the earlier FCC v NCCB case in which the Supreme Court ruled that “diversity and its effects are… elusive concepts, not easily defined let alone measured without making qualitative judgments” ... out that he sides with FCC in that the Diversity Index is not the final rule, nor sole consideration, and as such should be given deference unless specifically shown to be unreasonable ... Therefore, any problems with the Diversity Index were insufficient to prevent the FCC rules from taking effect ...
Prometheus Radio Project V. FCC - Prior History of Media Ownership Rules - 2002 Biennial Review and 2003 Report and Order - Diversity Index
... The index was based on the Herfindahl Index (HHI), which is used by the Federal Trade Commission and Department of Justice to measure market concentration ... Included in the Diversity Index are broadcast television, newspapers, radio, and internet ... types for each owner was then squared and added to the index ...
Diversity Index - Rényi Entropy
... This means that taking the logarithm of true diversity based on any value of q gives the Rényi entropy corresponding to the same value of q ...
... indices commonly used to characterize bio-diversity have been made (Ibánez et al ... (1995) first introduced ecological diversity indices as measures of pedodiversity ... They include Species richness, abundance, and Shannon index ...

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