String-Matching

• Beider-Morse Phonetic Matching

  Beider-Morse Phonetic Matching (BMPM) is a rule-based phonetic algorithm designed for Jewish surnames, applying language-specific phonological rules to match names across Yiddish, Hebrew, Russian, Polish, German, and other languages.

• Cologne Phonetics

  Cologne Phonetics (Kölner Phonetik) is a German phonetic algorithm that maps names to numeric codes, enabling phonetic matching across German spelling variations that Soundex cannot handle.

• Daitch-Mokotoff Soundex

  A Soundex variant developed for Slavic and Yiddish surnames that produces a six-digit numeric code and can return multiple codes per name to handle ambiguous digraph pronunciations.

• Match Rating Approach

  The Match Rating Approach encodes a name into a codex and then compares two codices using a defined similarity rating, returning a boolean match decision rather than leaving comparison to the caller.

• NYSIIS

  NYSIIS is a phonetic encoding algorithm developed in 1970 that maps names to letter-based codes, producing more accurate matches for North American names than Soundex.

• Caverphone

  Caverphone is a phonetic encoding algorithm designed for New Zealand English names, producing a 10-character code to match name variants across historical records.

• Double Metaphone

  Double Metaphone extends the original Metaphone algorithm by producing two phonetic codes per word — a primary and a secondary — to handle pronunciation ambiguity and non-English name patterns.

• Metaphone

  Metaphone encodes an English word into a variable-length string of consonant sounds, applying context-sensitive phonological rules that allow names with different spellings but similar pronunciations to match.

• Metaphone 3

  Metaphone 3 is a commercial phonetic algorithm by Lawrence Philips that extends Double Metaphone with a substantially larger rule set, claiming around 98% accuracy on English and European names.

• Phonetic Encoding

  Phonetic encoding maps a word to a compact code that represents its pronunciation, so that words which sound alike but are spelled differently produce the same code and match one another.

• Soundex

  Soundex maps a name to a four-character code — one letter plus three digits — so that names with similar pronunciations but different spellings produce the same code and match one another.

• Lovins Stemmer

  The Lovins Stemmer is the earliest published stemming algorithm (1968), reducing English words to stems in a single pass by stripping the longest matching suffix from a table of 294 rules.

• Paice/Husk Stemmer

  The Paice/Husk Stemmer is an iterative English stemmer using a single compact rule table with a loop-back architecture, producing aggressively short stems at the cost of over-stemming.

• Porter Stemmer

  The Porter Stemmer is a rule-based English suffix-stripping algorithm that reduces words to a stem using five sequential transformation passes gated by a vowel-consonant measure.

• Porter2 Stemmer

  Porter2 is a revised English suffix-stripping algorithm from the Snowball project that fixes around 200 mis-stemmings in the original Porter Stemmer and is the default stemmer in Elasticsearch’s english analyser.

• Unicode Normalisation

  Unicode normalisation resolves the fact that a single visible character can be encoded multiple ways, standardising text to one of four forms — NFC, NFD, NFKC, or NFKD — before comparison, indexing, or hashing.