An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) General: Leaning of the mind toward or away from something; especially: a personal and sometimes unreasoned judgment.
Statistics: A → systematic error introduced by selecting items from a wrong population, favoring some of the elements of a population, or poorly phrasing questions.
2) Electronics: A → voltage applied to a device to establish a reference level for operation. Same as initial voltage, initial tension (Ger. die Vorspannung). In a → CCD detector, electronic → offset which prevents negative signal.
3a) General: To give a settled and often prejudiced outlook to.
3b) Electronics: To apply a small voltage to a device to control its operation. See also: → bias error, → bias frame, → bias offset, → bias voltage, → biased, → biased estimate, → biased galaxy formation, → biased sample, → biased statistics, → debias, → kinematic bias, → Lutz-Kelker bias, → Malmquist bias, → observational bias, → sampling bias, → unbiased, → unbiased estimator.

From M.Fr. biais "slant," perhaps ultimately from Gk. epikarsios "slanting, oblique," from epi- "upon" + karsios "oblique."

Varak, from var "side, direction" + -ak suffix denoting relation, affinity, similarity (as in dastak, poštak, pašmak, xarak, nâxonak, mušak, eynak). Note also var in yekvar "slanting, inclined".
Pištaneš, only in the electronic sense, from piš, → pre- + taneš, → tension.
Varak dâdan, from varak + dâdan "to give," → datum.

A measurement error that remains constant in magnitude for all observations; for example an incorrectly set zero adjustment.

→ bias; → error.

CCD frame with exposure time set to zero and giving the bias level.

→ bias; → frame.

Nurdâd, → exposure; varak→ bias

In → CCD detectors, same as → bias and → offset.

→ bias; → offset.

A voltage applied or developed between two electrodes as a bias.

→ bias; → voltage.

Marked by or exhibiting bias; characterized by settled and often prejudiced outlook.

Biased, from → bias + adj. suffix -ed.

Varakdâr, from varak, → bias + -dâr "possessing, having," from dâštan "to possess, to have."

Of a population parameter, if the mean or expectation of the statistics is not equal to the parameter.

→ biased; → estimate.

barâvard, → estimate; varakdâr→ biased.

The theory that bright galaxies form preferentially from anomalously overdense perturbations in the → early Universe.

→ biased; → galaxy; → formation.

A sample that is not a true representative of a → statistical population to which generalizations are to be made. A sample which is not → randomly constituted.

→ biased; → sample.

A statistics based on a → biased sample.

→ biased; → statistics.

To substract the → bias from a flat-field or science frame obtained using an electronic detector.

Debias, from → de- + → bias.

Varak zodudan, from varak→ bias + zodudan "to polish, clean," Mid.Pers. uzdātan, Av. uzdā-, from uz-, → ex-, + dā- "make, create."

The process of removing the → bias from a → flat-field or science → frame. → debias

Verbal noun of → debias.

A systematic error introduced in a sample of stellar → proper motion data by higher velocity stars that are easier to measure.

→ kinematic; → bias.

A systematic error that can be introduced when → trigonometric parallaxes are used to calibrate a luminosity system. The bias arises when stars are selected by a lower limit in the observed parallax values. This favors the stars for which the measured parallax result is relatively too large.

Named after Th. Lutz & D.H. E. Kelker, 1973, PASP 85, 573; → bias.

A selection effect in observational astronomy. If a sample of objects (galaxies, quasars, stars, etc.) is flux-limited, then the observer will see an increase in average luminosity with distance, because the less luminous sources at large distances will not be detected.

Named after the Swedish astronomer Gunnar Malmquist (1893-1982); → bias.

An error in observation arising from systematically favoring brighter or weaker objects or some particular object morphologies; e.g. → Malmquist bias.

→ observational; → bias.

That part of the difference between the expected value of the sample estimator and the true value of the characteristic which results from the sampling procedure, the estimating procedure, or their combination.

→ sampling; → bias.

Not biased or prejudiced.
Statistics: With an expected value that is equal to the parameter being estimated.

→ un- + → biased.

Bi- "without" + varak, → bias.

A sample statistics when the mean of the sampling distribution of that statistic can be shown to be equal to the parameter being estimated.

→ unbiased; → estimator.

A sample in which every individual element in the population has an equal chance of being selected.

→ unbiased; → sample.