Metafore
Le metafore vengono usate per esprimere concetti nuovi o astratti in termini di
altri più familiari. Nel mondo dei calcolatori ha avuto un enorme successo
l'introduzione della metafora del desktop (modello della scrivania)
in cui lo schermo di un calcolatore è visto come la scrivania di un ufficio.
Così facendo si introduce un modello di interazione familiare all'utente.
Gli oggetti (icone) sono assimilati agli oggetti che ci sono
su una scrivania, oggetti sui quali si può agire direttamente.
Si introduce così il concetto di manipolazione diretta:
gli oggetti rappresentati sullo schermo in maniera simbolica
sono trattati come nel mondo reale (ad esempio, per cancellare un file si
trascina l'icona che lo rappresenta sul cestino della spazzatura).
Facendo una ricerca con parola chiave metaphor
nel sito www.webopedia.com si ottengono le seguenti definizioni.
- Desktop
In graphical user interfaces, a desktop is the
metaphor used to portray file systems. Such a desktop
consists of pictures, called icons, that show cabinets,
files, folders, and various types of documents (that is,
letters, reports, pictures). You can arrange the icons on
the electronic desktop just as you can arrange real
objects on a real desktop -- moving them around,
putting one on top of another, reshuffling them, and
throwing them away.
- Cyberspace
A metaphor for describing the non-physical terrain created by computer
systems. Online systems, for example, create a cyberspace within which
people can communicate with one another (via e-mail), do research, or simply
window shop. Like physical space, cyberspace contains objects (files, mail
messages, graphics, etc.) and different modes of transportation and delivery.
Unlike real space, though, exploring cyberspace does not require any physical
movement other than pressing keys on a keyboard or moving a mouse.
Some programs, particularly computer games, are designed to create a
special cyberspace, one that resembles physical reality in some ways but
defies it in others. In its extreme form, called virtual reality, users are
presented with visual, auditory, and even tactile feedback that makes
cyberspace feel real.
The term was coined by author William Gibson in his sci-fi novel Neuromancer (1984).
- Compound document
A document that contains elements from a variety of computer applications.
For example, a single compound document might include text from a word
processor, graphics from a draw program, and a chart from a spreadsheet
application. Most importantly, each element in the compound document is
stored in such a way that it can be manipulated by the application that
created it.
Many computer experts believe that compound documents represent the
most useful metaphor for utilizing computers because they allow people
to mix different forms of expression rather than artificially separating them.
With the emergence of OLE as an important standard, compound documents are
likely to become more and more a part of everyday computing.
- Chat room
A virtual room where a chat session takes place. Technically, a chat room is
really a channel, but the term room is used to promote the chat metaphor.
- Visual Basic
A programming language and environment developed by Microsoft. Based on
the BASIC language, Visual Basic was one of the first products to provide a
graphical programming environment and a paint metaphor for developing user
interfaces. Instead of worrying about syntax details, the Visual Basic
programmer can add a substantial amount of code simply by dragging and
dropping controls, such as buttons and dialog boxes, and then defining their
appearance and behavior.
Although not a true object-oriented programming language in the strictest
sense, Visual Basic nevertheless has an object-oriented philosophy. It is
sometimes called an event-driven language because each object can react to
different events such as a mouse click.
Since its launch in 1990, the Visual Basic approach has become the norm for
programming languages. Now there are visual environments for many
programming languages, including C, C++, Pascal, and Java. Visual Basic is
sometimes called a Rapid Application Development (RAD) system because it
enables programmers to quickly build prototype applications.
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