R. E. Tulloss and D. C. Tulloss

The similarity metric implemented on this page is a beta version of the tripartite similarity metric originally described by R. E. Tulloss (1997. Assessment of Similarity Indices for Undesirable Properties and Proposal of a New Index Based on Cost Functions in M. E. Palm and I. H. Chapela, eds. Mycology in Sustainable Development: 122-143). The motivation for such a metric is stated in the paper.

The mathematical core of the similarity metric implemented in these pages is described in the cited paper. What has been added are input and output functions that simplify the use of the metric. The purpose is to allow a user to enter two or more titled lists for purposes of generating similarity indices for the lists considered a pair at a time. All pairs of lists (ignoring the ordering of the lists in a pair) are compared. The similarity index values fall between 0 and 1. A similarity index value of 0 indicates that two lists contain no elements in common. A similarity index value of 1 indicates that they are identical. The mathematical properties of the index are discussed and sample responses to input data are provided in the cited paper.

The similarity indices calculated for a given set of lists are presented in the form of a table with its rows and columns labeled with the names of the lists. This output is downloadable to the user's own computer.

The user should read instructions concerning the four input forms available for the similarity calculator. The calculator in all its forms is accessed from the page entitled "Calculations." Eventually, we will add suggestions from a variety of sources that educators and students may find of interest in exploring the similarity calculator.

We suggest this page be cited in bibliographies as follows:

Tulloss, R. E. and D. C. Tulloss. current_year. Tripartite Similarity Calculator. (your_access_date).

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Perform new calculations and review and edit past ones.
Calculations Data Editor
An overview of all your data. You can edit and manage your calculations, lists and list items.
Calculations List Manager
Manage your data lists and perform new calculations from old lists.
Index of discussions relevant to similarity and other "coefficients of association."
Learn how to use use the four data entry modes and other features of the software such as data management or data recycling and biogeographic affinity analysis.
Teaching & Application
[t.b.d.] Uses of similarity metrics will be discussed, and interesting uses in classroom and research environments will be posted. Present content: "starter" bibliography re applications of the tripartite similarity metric.

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