## Accuracy and precision |

**Precision** is a description of * random errors*, a measure of

**Accuracy** has two definitions:

- More commonly, it is a description of
, a measure ofsystematic errors statistical bias ; as these cause a difference between a result and a "true" value,ISO calls this*trueness*. - Alternatively, ISO defines accuracy as describing a combination of both types of
observational error above (random and systematic), so high accuracy requires both high precision and high trueness.

In simplest terms, given a set of data points from repeated measurements of the same quantity, the set can be said to be *precise* if the values are close to each other, while the set can be said to be *accurate* if their average is close to the *true value* of the quantity being measured. In the first, more common definition above, the two concepts are independent of each other, so a particular set of data can be said to be either accurate, or precise, or both, or neither.

- common technical definition
- iso definition (iso 5725)
- in binary classification
- in psychometrics and psychophysics
- in logic simulation
- in information systems
- see also
- references
- external links

In the fields of ^{[1]} The precision of a measurement system, related to ^{[1]}^{[2]} Although the two words precision and accuracy can be

The field of * bias* and

A measurement system can be accurate but not precise, precise but not accurate, neither, or both. For example, if an experiment contains a

A measurement system is considered *valid* if it is both *accurate* and *precise*. Related terms include *bias* (non-*error* (random variability).

The terminology is also applied to indirect measurements—that is, values obtained by a computational procedure from observed data.

In addition to accuracy and precision, measurements may also have a

In

In military terms, accuracy refers primarily to the accuracy of fire (or "justesse de tir"), the precision of fire expressed by the closeness of a grouping of shots at and around the centre of the target.^{[3]}

In industrial instrumentation, accuracy is the measurement tolerance, or transmission of the instrument and defines the limits of the errors made when the instrument is used in normal operating conditions.^{[4]}

Ideally a measurement device is both accurate and precise, with measurements all close to and tightly clustered around the true value. The accuracy and precision of a measurement process is usually established by repeatedly measuring some

This also applies when measurements are repeated and averaged. In that case, the term

With regard to accuracy we can distinguish:

- the difference between the
mean of the measurements and the reference value, thebias . Establishing and correcting for bias is necessary forcalibration . - the combined effect of that and precision.

A common convention in science and engineering is to express accuracy and/or precision implicitly by means of

A reading of 8,000 m, with trailing zeroes and no decimal point, is ambiguous; the trailing zeroes may or may not be intended as significant figures. To avoid this ambiguity, the number could be represented in scientific notation: 8.0 × 10^{3} m indicates that the first zero is significant (hence a margin of 50 m) while 8.000 × 10^{3} m indicates that all three zeroes are significant, giving a margin of 0.5 m. Similarly, it is possible to use a multiple of the basic measurement unit: 8.0 km is equivalent to 8.0 × 10^{3} m. In fact, it indicates a margin of 0.05 km (50 m). However, reliance on this convention can lead to

Precision includes:

*repeatability*— the variation arising when all efforts are made to keep conditions constant by using the same instrument and operator, and repeating during a short time period; and*reproducibility*— the variation arising using the same measurement process among different instruments and operators, and over longer time periods.

Other Languages

العربية: الدقة والضبط

azərbaycanca: Dəqiqlik

Bân-lâm-gú: Chún-khak kah cheng-bi̍t

català: Exactitud i precisió

Deutsch: Genauigkeit

eesti: Täpsus ja kordustäpsus

español: Precisión y exactitud

Esperanto: Ekzakteco kaj precizeco

فارسی: صحت و دقت

한국어: 정확도와 정밀도

हिन्दी: यथार्थता एवं परिशुद्धता

Bahasa Indonesia: Akurasi dan presisi

עברית: דיוק ונכונות

қазақша: Дәлдік

magyar: Pontosság és precizitás

Nederlands: Nauwkeurigheid

日本語: 正確度と精度

română: Exactitate și precizie

русский: Точность

Simple English: Accuracy and precision

slovenčina: Presnosť merania

slovenščina: Točnost in natančnost

српски / srpski: Прецизност и тачност

srpskohrvatski / српскохрватски: Tačnost i ponovljivost

Basa Sunda: Akurasi jeung présisi

suomi: Tarkkuus

Türkçe: Doğruluk ve kesinlik

українська: Точність

中文: 準確與精密