DICO Project ISSCO - University of Geneva

simplicity: tool that enables non-specialist users to lookup entries in dictionaries.

accessibility: it should work in an environment of networked heterogeneous computers.

expandability: it should be easy to add data, indexes.

robustness: it should be resistant to hazards inherent to networks and inexperienced users

General Design

Communication Protocol

Advantages of a client-server design

Interfaces

Indexes

Display

Transducer

Dictionary source representation

Alphabetical order

Approximate matching

Special characters

Summary

HotDico

• A Dictionary Information Service (DIS)
• A dictionary servers
• A client user interface,

• A server can handle many clients.
• There can be many servers on the network.

the client sends a request to the server, and waits until the server processes it and sends back an answer.

For example:

• Ask for the list of available dictionaries.
• Change the current dictionary.
• Ask for the list of entries corresponding to a given search key.
• Ask for the content of an entry.
• Ask for next or previous entry in the alphabetical order
• Change the format for displaying entries
• Ask for a help or information page

• Access through the network
• The work is split in two
  • The user interface handles query editing, display of the entries, local configuration.
  • The server handles database operations
• expandability: different user interfaces can be developed for different purpose or computers:
  • X-windows (xdico)
  • full screen character terminal (tdico)
  • java user interface (HOTDico)
• One copy of the dictionary data
  • saves disk space and maintenance time
  • better protection of data

• Java Interface

  This interface has been redefined to adopt the new concept of Virtual language Reference Library and has been completely recoded with the programming language Java. The choice of an interpreted language like these has the major interest that it's widely available on all common platforms and operating systems.

• X-Windows client

  Allows typographical display of entries (various font styles, etc.) allows select-paste. Adds an extra stretch of network access because the interface can be displayed on a remote screen. Customizable via the X resources Uses basic X11R5 tools for portability

• Terminal client

  Mimics windows using the full screen capabilities of the character terminal Keyboard keys for buttons and menus Typographical aspect rendition with character attributes (underlined, inverse video, standout mode) Accommodates almost all terminals with addressable cursor (thanks to UNIX curses package). Adds an extra stretch of network access when using a terminal emulator and connecting with telnet or a modem

Main index implementation

• Homographs correspond to different entries
• Spelling variants correspond to the same entry

• By full headword (binary search)
• By a prefix of headword (binary search)
• By a regular expression pattern (sequential search).

Secondary index implementation

• Arbitrary keys: it does not have to appear in the content of an entry
• Creation of an index is done off-line, and may involve external data and heavy processing

Examples:

• Domain information codes (BIOLOGY, THEATRE)
• Reverse index: all words appearing in the definition or translation part of a word (possibly lemmatized). synonyms, or thesaurus.

Advantages of this index design

• Simplicity: few constraint on the dictionary representation:
  • The content of an entry is contiguous
  • Entries in one file, in any order, not necessarily contiguous
  • No significant limits (but those of the hardware and software environment) to the size of an entry or their number.
• Expandability: new secondary indexes can be added easily
• Fast: main index is in shared memory, sorted, secondary indexes are hashcoded (the real work is done off-line, only once).

Transducer rules are interpreted.

Display Representation

Advantages of the transducer

• Few constraints on dictionary source format: entries should have be uniform so that one set of rules can convert them all. The automaton is powerful enough to accommodate complex coding.
• Choice of display format, for example:
  • Variants of layout
  • Outline source
• Expandability: new display formats (i.e. new set of rules) can be added easily.
• Formatting is done by the client:
  • Unload the server
  • Allow compact source entries: unload the network

• Word processing format
• Optical character recognition
• Hand typed from printed version

• There are errors in the representation (typographical, file corruption)
• The structure of similar entries is not consistent (different lexicographers at different times)
• Easy clues are few: you need language understanding to disambiguate some constructions.

The Text Encoding Initiative will give guidelines on how to code printed dictionaries for exchange purposes.

• Different alphabets: in Danish æ, ø, å are sorted after z
• Grouped letters: in Spanish ch is sorted after cz and ll after lz
• Secondary sort: in French the accent on a character is used as a secondary key. Example:

  mais.......mais.......i.....(but)

  maïs.......mais.......ï.....(corn)

  maison..maison...i.....(house)

• Ignore case (optional): a matches a or A
• Ignore accents (optional): e matches e, é, è, ë, ê
• Ignore punctuation and spaces:
  • bb or b&b matches b.&b.
  • crowsnest matches crow's nest

This is described together with the alphabetical order rules:

• Dictionary specific
• Easily modified

Sometimes the user's equipment or his inexperience does not allow typing or displaying special characters.

• Input: an option allows to type two characters to compose one.

  pair...........character

  a`...................à

  n~.................ñ

• Output: an option controls how special characters are displayed.

  char.......bad...long name.........pair

  é...............i..........e-acute...........e'

• Attention to details makes the client interfaces usable to people with different skills and with diverse computer equipment.
• Good accessibility through the network thanks to the client-server design.
• Remarkable design features are:
  • Client-server
  • Transducer
  • Access to many dictionaries through the same interface
  • Language independent

Eight dictionaries installed:

• Collins GEM
  • English ´ French (6972, 5808)
  • English ´ German (707, 763)
  • French ´ German (443, 585)
• Dictionary of Current Idiomatic English (Volume 1: verbs and Volume 2: phrases)
• French-SwissGerman