Dictionaries

A dictionary (also called a wordstock, word reference, wordbook, lexicon, or vocabulary) is a collection of words in one or more specific languages, often listed alphabetically (or by radical and stroke for ideographic languages), with usage information, definitions, etymologies, phonetics, pronunciations, and other information; or a book of words in one language with their equivalents in another, also known as a lexicon. According to Nielsen (2008) a dictionary may be regarded as a lexicographical product that is characterised by three significant features: (1) it has been prepared for one or more functions; (2) it contains data that have been selected for the purpose of fulfilling those functions; and (3) its lexicographic structures link and establish relationships between the data so that they can meet the needs of users and fulfill the functions of the dictionary.

A broad distinction is made between general and specialized dictionaries. Specialized dictionaries do not contain information about words that are used in language for general purposes&mdash;words used by ordinary people in everyday situations. Lexical items that describe concepts in specific fields are usually called terms instead of words, although there is no consensus whether lexicology and terminology are two different fields of study. In theory, general dictionaries are supposed to be semasiological, mapping word to definition, while specialized dictionaries are supposed to be onomasiological, first identifying concepts and then establishing the terms used to designate them. In practice, the two approaches are used for both types. There are other types of dictionaries that don't fit neatly in the above distinction, for instance bilingual (translation) dictionaries, dictionaries of synonyms (thesauri), or rhyming dictionaries. The word dictionary (unqualified) is usually understood to refer to a monolingual general-purpose dictionary.

A different dimension on which dictionaries (usually just general-purpose ones) are sometimes distinguished is whether they are prescriptive or descriptive, the latter being in theory largely based on linguistic corpus studies&mdash;this is the case of most modern dictionaries. However, this distinction cannot be upheld in the strictest sense. The choice of headwords is considered itself of prescriptive nature; for instance, dictionaries avoid having too many taboo words in that position. Stylistic indications (e.g. ‘informal’ or ‘vulgar’) present in many modern dictionaries is considered less than objectively descriptive as well.

Although the first recorded dictionaries date back to Sumerian times (these were bilingual dictionaries), the systematic study of dictionaries as objects of scientific interest themselves is a 20th-century enterprise, called lexicography, and largely initiated by Ladislav Zgusta. The birth of the new discipline was not without controversy, the practical dictionary-makers being sometimes accused of "astonishing" lack of method and critical-self reflection.

Dictionaries of interest to psychologists

 * DISCO - European Dictionary of Skills and Competences

Types
In a general dictionary, each word may have multiple meanings. Some dictionaries include each separate meaning in the order of most common usage while others list definitions in historical order, with the oldest usage first.

In many languages, words can appear in many different forms, but only the undeclined or unconjugated form appears as the headword in most dictionaries. Dictionaries are most commonly found in the form of a book, but some newer dictionaries, like StarDict and the New Oxford American Dictionary are dictionary software running on PDAs or computers. There are also many online dictionaries accessible via the Internet.

Specialized dictionaries
According to the Manual of Specialized Lexicographies a specialized dictionary (also referred to as a technical dictionary) is a lexicon that focuses upon a specific subject field. Following the description in The Bilingual LSP Dictionary lexicographers categorize specialized dictionaries into three types. A multi-field dictionary broadly covers several subject fields (e.g., a business dictionary), a single-field dictionary narrowly covers one particular subject field (e.g., law), and a sub-field dictionary covers a singular field (e.g., constitutional law). For example, the 23-language Inter-Active Terminology for Europe is a multi-field dictionary, the American National Biography is a single-field, and the African American National Biography Project is a sub-field dictionary. In terms of the above coverage distinction between "minimizing dictionaries" and "maximizing dictionaries", multi-field dictionaries tend to minimize coverage across subject fields (for instance, Oxford Dictionary of World Religions) whereas single-field and sub-field dictionaries tend to maximize coverage within a limited subject field (The Oxford Dictionary of English Etymology).

Another variant is the glossary, an alphabetical list of defined terms in a specialised field, such as medicine (medical dictionary).

Defining dictionaries
The simplest dictionary, a defining dictionary, provides a core glossary of the simplest meanings of the simplest concepts. From these, other concepts can be explained and defined, in particular for those who are first learning a language. In English, the commercial defining dictionaries typically include only one or two meanings of under 2000 words. With these, the rest of English, and even the 4000 most common English idioms and metaphors, can be defined.

Prescriptive vs. descriptive


Lexicographers apply two basic philosophies to the defining of words: prescriptive or descriptive. Noah Webster, intent on forging a distinct identity for the American language, altered spellings and accentuated differences in meaning and pronunciation of some words. This is why American English now uses the spelling color while the rest of the English-speaking world prefers colour. (Similarly, British English subsequently underwent a few spelling changes that did not affect American English; see further at American and British English spelling differences.)

Large 20th-century dictionaries such as the Oxford English Dictionary (OED) and Webster's Third are descriptive, and attempt to describe the actual use of words. Most dictionaries of English now apply the descriptive method to a word's definition, and then, outside of the definition itself, add information alerting readers to attitudes which may influence their choices on words often considered vulgar, offensive, erroneous, or easily confused. Merriam-Webster is subtle, only adding italicized notations such as, sometimes offensive or nonstand (nonstandard.) American Heritage goes further, discussing issues separately in numerous "usage notes." Encarta provides similar notes, but is more prescriptive, offering warnings and admonitions against the use of certain words considered by many to be offensive or illiterate, such as, "an offensive term for..." or "a taboo term meaning..."

Because of the widespread use of dictionaries in schools, and their acceptance by many as language authorities, their treatment of the language does affect usage to some degree, with even the most descriptive dictionaries providing conservative continuity. In the long run, however, the meanings of words in English are primarily determined by usage, and the language is being changed and created every day. As Jorge Luis Borges says in the prologue to "El otro, el mismo": "It is often forgotten that (dictionaries) are artificial repositories, put together well after the languages they define. The roots of language are irrational and of a magical nature."

Dictionaries for natural language processing
In contrast to traditional dictionaries, which are designed to be used by human beings, dictionaries for natural language processing (NLP) are built to be used by computer programs. (The final user is a human being but the direct user is a program.) Such a dictionary does not need to be able to be printed on paper. The structure of the content is not linear, ordered entry by entry but has the form of a complex graph. Because most of these dictionaries are used to control machine translations or cross-lingual information retrieval (CLIR) the content is usually multilingual and usually of huge size. In order to allow formalized exchange and merging of dictionaries, an ISO standard called Lexical Markup Framework (LMF) has been defined and used among the industrial and academic community.

Other types

 * Bilingual dictionary
 * Electronic dictionary
 * Encyclopedic dictionary
 * Monolingual learner's dictionary
 * Advanced learner's dictionary
 * By sound
 * Phonetic dictionary
 * Rhyming dictionary
 * Reverse dictionary
 * Visual dictionary