A partial matching method for a fully automated directory assistance system using touch-tone telephones as input devices

✍ Scribed by Masahiro Oku; Ryoji Nagai; Ryousuke Noda; Tomosada Hayashi; Masanobu Higashida

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 274 KB
• Volume: 33
• Category: Article
• ISSN: 0882-1666
• DOI: 10.1002/scj.1129

✦ Synopsis

Abstract

We have been developing a fully automated Japanese directory assistance system using touch‐tone telephones as input devices. This system is characterized by a newly developed input interface, called the degenerated keyword input method, which reduces the user's input workload. This input method associates one push on a button with one character of kana (Japanese syllabary). Since each touch‐tone button on a telephone can represent several different kana characters, using a touch‐tone numeral string as the search keyword inevitably leaves some ambiguity. This paper proposes a partial matching method, which is especially suitable for the fully automated Japanese directory assistance system. This method eliminates ambiguity in the degenerated keyword inputs and allows fast and highly accurate database searching. The method features the following. (1) It focuses on the PAT‐tree in the field of full‐text searching, and derives modified semi‐infinite strings (sistrings) at a word level, rather than at a character level, in the PAT‐tree for each record. (2) Word boundaries are marked in the index records, and only those candidates whose word boundary position coincides with the last character of the search keyword are selected as retrieval results. This use of word boundaries reduces retrieval noise. This paper also describes the results of evaluation experiments conducted to validate the proposed method. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(6): 19–31, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1129