Big Data and Cross-Document Coreference Resolution: Current State and Future Opportunities
Table 2: Soundex encoding table.
['Consonants b, f, p, v', 'Number 1', 'Consonants l', 'Number 4']
Soundex [HolmesM02], one of the best known phonetic functions, converts a string into a code according to an encoding table. A soundex code is comprised of one character and three numbers. The Soundex code is generated as follows: (i) Keep the first letter of a string and ignore all other occurrences of vowels (a, e, i, o, u) and h, w, y; (iii) Code two consecutive letters as a single number; and (iv) Pad with 0 if there are less than three numbers. For example, using the soundex encoding table, both “daniel” and “damiel” return the same soundex code “d540”. Phonex/Phonix [Randell93] is an alternative function to Soundex, which was designed to improve the encoding quality by preprocessing names based on their pronunciations. Phonix [Gadd1990], an extension of Phonex, uses more than one hundred rules on groups of characters [Christen06]. The rules are applied to only some parts of names, e.g., the beginning, middle or end of names. Double Metaphone [Philips] performs better for string matching in non-English languages, like European and Asian, rather than the soundex function that is suitable for English. Thus it uses more complex rules that consider letter positions as well as previous and following letters in a string, compared with the soundex function.