2. Computational Lexicography. Electronic Dictionaries

Computational lexicography deals with the design, compilation, use and evaluation of electronic (electronically readable/machine readable) dictionaries. Electronic dictionaries fundamentally differ in form, content, and function from conventional word-books. Among the most significant differences are: 1) the use of multimedia means; 2) the navigable help indices in windows oriented software; 3) the use of sound, animation, audio and visual (pictures, videos) elements as well as interactive exercises and games; 4) the varied possibilities of search and access methods that allow the user to specify the output in a number of ways; 5) the access to and retrieval of information are no longer determined by the internal, traditionally alphabetical, organization of the dictionary, but a non-linear structure of the text; 6) the use of hyperlinks which allow easily and quickly to cross-refer to words within an entry or to other words connected with this entry.

In case of electronic dictionaries the demands on the user become greater as the emphasis is less on following a predetermined path through the dictionary structure and more on navigating relationships across and within entries via a choice of links. So before using an electronic dictionary it is necessary to acquire certain navigational and searching skills apart from the ‘conventional dictionary skills’. The difference between the minimal skills acquired for the use of conventional and electronic dictionaries is given in table.

Dictionaries in book form	Electronic dictionaries
1. Understanding the structure of paper-based dictionary	1. Understanding the presentation in windows on a computer screen
2. Knowing how to use the Guide to the book dictionary	2. Knowing how to use the Help facility
3. Understanding of typographical conventions and the use of symbols and punctuation	3. Knowing how to use hyperlinks (e.g. to display the full term shown in pop-up windows)
4. Deciding what to look up	4. Deciding on the type of search: headword, filtered or full text search; and understanding how advanced searches work
5. Knowing how to interpret the international phonetic alphabet (IPA) and pronunciation of words	5. Knowing how to use the Audio facility
6. Distinguishing relevant from irrelevant information	6. Knowing how to confine searches to the information required
7. Scanning dictionary entries	7. Restricting search to particular sections, e.g. to idioms and phrasal verbs
8. Knowing how to carry out cross-references	8. Knowing how to use hypertext links
9. Referring to additional information in front matter or appendices	9. Referring to additional information in various sections presented on the screen
10. Recording the dictionary information	10. Recording the dictionary information in electronic form using the link to Microsoft Word and the Copy-function

There are distinguished two main types of electronic dictionaries: online dictionaries and CD-ROM dictionaries. To use on-line dictionaries it is necessary to have access to the Internet. To install CD-ROM dictionaries on a computer it is necessary to ensure that a computer meets the minimum system requirements that are usually enumerated in the User Guide.

Among the on-line dictionaries there are the following: the Oxford English Dictionary Online, the Merriam- Webster Online Dictionary, the Cambridge Dictionaries Online (including Cambridge Advanced Learner’s Dictionary, Cambridge International Dictionary of Idioms, Cambridge Dictionary of American English, etc.), the American Heritage Dictionary of the English language and many others. Each dictionary has its own benefits and differs, sometimes greatly, in the interface, material available, contents area, number of options, organization of entries, search capabilities, etc. from other dictionaries of such kind.

The Oxford English Dictionary Online, for instance, contains the material of the 20-volume Oxford English Dictionary and 3-volume Additions Series. Besides more revised and new entries are added to the online dictionary every quarter. The layout of a typical entry window is given below. The Oxford English Dictionary Online is characterized by the following main features: 1) the display of entries according to a user’s needs, i.e. entries can be displayed by turning pronunciations, etymologies, variant spellings, and quotations on and off; 2) the search for pronunciations as well as accented and other special characters; 3) the search for words which have come into English via a particular language; 4) the search for quotations from a specified year, or from a particular author and/or work; 5) the search for a term when a user knows only meaning; 6) the use of wildcards’ if a user is unsure of a spelling; 7) the restrictions of a search to a previous results set; 8) the search for first cited date, authors, and works; 9) the case-sensitive searches; and some others.

Among the CD-ROM dictionaries there are the following: the Longman Dictionary of Contemporary English on CD-ROM, the Cambridge International Dictionary of English on CD-ROM, the Collins COBUILD on CD-ROM, the Concise Oxford Dictionary on CD-ROM, and many others.

In most cases CD-ROM dictionaries are electronic versions of the printed reference books supplemented by more visual information, pronunciation, interactive exercises and games and allowing the user to carry out searches impossible with the book dictionaries.

The Longman Dictionary of Contemporary English on CD-ROM, for example, differs from the paper dictionary in the following way: 1) every word is pronounced in British and American English. A user can also record his/her own pronunciation and compare it with the accepted form; 2) it gives 15,000 word origins or etymologies and contains 7000 encyclopedic entries for people, places, and things, taken from the Longman Dictionary of English Language and Culture; 3) there are 80,000 additional examples given in the Longman Examples Bank; 4) over a million corpus sentences are included for very advanced learners and teachers of English; 5) it contains 150,000 extra words (collocates) that are used with the headword; 6) it has the Activator section which is very helpful in choosing the right word in this or that context and provides essay writing technique; 7) there are a lot of interactive activities in grammar, vocabulary, culture, as well as exam practice exercises.

The Longman Dictionary of Contemporary English on CD-ROM has its own distinctive features that make it prominent among the dictionaries of this kind. There are three main functions in the CD-ROM dictionary, each opening in the main window but with a slightly different look. These three functions are the Dictionary, Activator, and Exercises. Users can choose the full sized display, or "Pop-Up Mode". The dictionary interface includes a search bar, an area for viewing entries, and windows for the Phrase Bank, Examples Bank, and the Activate Your Language tool.

In the entry display (left side of the screen), the word is presented along with links to pronunciation, usage note, word origin, verb form, and word set, but not all links are active for all entries. The Phrase Bank includes phrases that use the search word, as well as words that are commonly used with the search word. The Examples Bank presents samples of the word’s usage from “Extra dictionary examples” and “Sentences from books, newspapers, etc.” The Activate Your Language section, which does not have entries for all words, allows a user to continue the search in the Activator.

In lexicography the developments in electronic instrumentation and computer science have revolutionized the dictionary-making process, shown new perspectives in this field, supported lexicographical studies in different directions.