Daitch–Mokotoff Soundex (D–M Soundex) is a
phonetic algorithm A phonetic algorithm is an algorithm for indexing of words by their pronunciation. Most phonetic algorithms were developed for English and are not useful for indexing words in other languages. Because English spelling varies significantly dependi ...
invented in 1985 by Jewish genealogists
Gary Mokotoff and
Randy Daitch. It is a refinement of the Russell and American
Soundex
Soundex is a phonetic algorithm for indexing names by sound, as pronounced in English. The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling. The algorithm mainly enc ...
algorithms designed to allow greater accuracy in matching of
Slavic and
Yiddish
Yiddish (, or , ''yidish'' or ''idish'', , ; , ''Yidish-Taytsh'', ) is a West Germanic language historically spoken by Ashkenazi Jews. It originated during the 9th century in Central Europe, providing the nascent Ashkenazi community with a ve ...
surnames with similar
pronunciation
Pronunciation is the way in which a word or a language is spoken. This may refer to generally agreed-upon sequences of sounds used in speaking a given word or language in a specific dialect ("correct pronunciation") or simply the way a particular ...
but differences in spelling.
Daitch–Mokotoff Soundex is sometimes referred to as "Jewish Soundex" and "Eastern European Soundex", although the authors discourage use of these nicknames for the algorithm because the algorithm itself is independent of the fact that the motivation for creating the new system was the poor result of predecessor systems when dealing with Slavic and Yiddish surnames.
Improvements
Improvements over the older Soundex algorithms include:
* Coded names are six digits long, resulting in greater search precision (traditional Soundex uses four characters)
* The initial character of the name is coded.
* Several rules in the algorithm encode multiple character n-grams as single digits (American and Russell Soundex do not handle multi-character n-grams)
* Multiple possible encodings can be returned for a single name (traditional Soundex returns only one encoding, even if the spelling of a name could potentially have multiple pronunciations)
Examples
Some examples:
Beider–Morse Phonetic Name Matching Algorithm
To address the large number of false positive results generated by the D–M Soundex,
Stephen P. Morse and
Alexander Beider created the Beider–Morse Phonetic Name Matching algorithm. This new algorithm cuts down on false positives at the expense of some false negatives. A number of sites are offering the B–M soundex in addition to the D-M soundex.
Nu? What's New? Volume 9, Number 22
Gary Mokotoff, Editor - The E-zine of Jewish Genealogy From Avotaynu
Notes
External links
* Mokotoff, Gary.
Describes the history and the motivations behind D–M Soundex.
* JewishGen.
Describes both Russel and D–M Soundex.
* Coles, Michael.
"SQL 2000 DBA Toolkit, Part 3: Phonetic Matching"
SQL Server-based implementation of the D–M Soundex algorithm w/source.
{{DEFAULTSORT:Daitch-Mokotoff Soundex
Phonetic algorithms
Genealogy