DICO Project
ISSCO - University of Geneva
DICO is a tool to consult multiple dictionaries or structured data on a computer network developped at ISSCO.
It is designed to accommodate various dictionary representations. In addition to a set of basic searching mechanisms, it allows easy addition of custom indexes. DICO was demonstrated at CeBIT'95 on the Swiss Technology Stand, and it is accessible on the network of the University of Geneva since 1992.

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

Table of Contents

General Design
Communication Protocol
Advantages of a client-server design
Dictionary source representation
Alphabetical order
Approximate matching
Special characters

General design

The tool is split in three parts communicating through the network

Communication protocol

The communication is driven by the client:

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

For example:

Advantages of a client-server design



In DICO, a dictionary is a collection of textual entries. Each entry is associated to at least one main access key (headword or headphrase) and possibly some secondary access keys (text).

Main index implementation

The main index is a N to N mapping of headwords to entries: The sorted list of headwords is kept in memory to allow for fast searches: Headwords can be displayed (include punctuation and spaces)

Secondary index implementation

The secondary index is a N to N mapping of access keys to entries. Search is done with full access key (by hashcode). Reference to the entries are kept in lists or bitmaps.


Advantages of this index design

Display format

Entries are formatted on the screen dynamically, according to the current dictionary, display format and screen width.

Transducer rules are interpreted.

Display Representation

Advantages of the transducer

Dictionary source representation

Dictionary on electronic media: Parsing is difficult because

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

Alphabetical order

Alphabetical order is apparent when displaying a list of matching headwords and when asking for the next or previous entry.Sorting rules are specific to each language: In DICO a description of the alphabetical order has to be associated to each dictionary.

Approximate matching

To allow for easy and forgiving entry of search keys It also allows for easy cut and paste from another document (or the definition part of an entry) when editing the search key.

This is described together with the alphabetical order rules:

Special characters

Currently DICO supports ISO-Latin1 alphabet and the IPA phonetic alphabet.

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


DICO is accessible on the network of the University of Geneva since 1992.

Eight dictionaries installed:

Information & Copyright

DICO (Copyright (c) ISSCO 1994,1995,1996),
Dominique PETITPIERRE Dominique.Petitpierre@unige.ch
Gilbert ROBERT Gilbert.Robert@issco.unige.ch
Intellectual property of ISSCO (University of Geneva) .

Last modified: 31st July 1996. Gilbert ROBERT