# Notation

(Redirected from Notation (disambiguation))

In linguistics and semiotics, a notation is a system of graphics or symbols, characters and abbreviated expressions, used inter alia in artistic and scientific disciplines to represent technical facts and quantities by convention.[1][2] Therefore, a notation is a collection of related symbols that are each given an arbitrary meaning, created to facilitate structured communication within a domain knowledge or field of study.

Standard notations refer to general agreements in the way things are written or denoted. The term is generally used in technical and scientific areas of study like mathematics, physics, chemistry and biology, but can also be seen in areas like business, economics and music.

## Written communication

• Phonographic writing systems, by definition, use symbols to represent components of auditory language, i.e. speech, which in turn refers to things or ideas. The two main kinds of phonographic notational system are the alphabet and the syllabary. Some written languages are more consistent in their correlation of written symbols (or graphemes) with sound (or phonemes), and are therefore considered to have better phonemic orthography.
• Ideographic writing, by definition, refers to things or ideas independently of their pronunciation in any language. Some ideographic systems are also pictograms that convey meaning through their pictorial resemblance to a physical object.

### Chemistry

• Chemical formulas are a way of expressing information about the atoms that constitute a particular chemical compound, e.g. H
2
O
or C
6
H
12
O
6

### Logic

A variety of symbols are used to express logical ideas; see the List of logic symbols

### Management

• Time and motion study symbols such as therbligs

### Physics

• Bra–ket notation, or Dirac notation, is an alternative representation of probability distributions in quantum mechanics.
• Tensor index notation is used when formulating physics (particularly continuum mechanics, electromagnetism, relativistic quantum mechanics and field theory, and general relativity) in the language of tensors.

### Typographical conventions

• Infix notation, the common arithmetic and logical formula notation, such as "a + bc".
• Polish notation or "prefix notation", which places the operator before the operands (arguments), such as "+ a b".
• Reverse Polish notation or "postfix notation", which places the operator after the operands, such as "a b +".

## Graphical notations

### Music

• Musical notation permits a composer to express musical ideas in a musical composition, which can be read and interpreted during performance by a trained musician; there are many different ways to do this (hundreds have been proposed), although staff notation provides by far the most widely used system of modern musical symbols.

### Science

• Feynman diagrams permit a graphical representation of a perturbative contribution to the transition amplitude or correlation function of a quantum mechanical or statistical field theory
• Structural formulas are graphical representations of molecules
• Venn diagrams shows logical relations between a finite collection of sets.
• Drakon-charts are a graphical representation of algorithms and procedural knowledge.