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Selection bias
| Glossary of Statistical Terms |
- A systematic tendency for a sampling procedure to include and/or exclude units of a certain type. for example, in a quota sample, unconscious prejudices or predilections on the part of the interviewer can result in selection bias. selection bias is a potential problem whenever a human has latitude in selecting individual units for the sample; it tends to be eliminated by probability sampling schemes in which the interviewer is told exactly whom to contact (with no room for individual choice).
- A systematic difference between a target population and the sample of data. for example, data mining on customer complaint databases has a selection bias in that the data only capture customers who were motivated and able to contact the manufacturer about their complaint and does not capture complaints or customers who were not motivated nor able. self organizing map (som) a self organizing map is a form of kohonen network that arranges its clusters in a (usually) two-dimensional grid so that the codebook vectors (the cluster centers) that are close to each other on the grid are also close in the k-dimensional feature space. the converse is not necessarily true, as codebook vectors that are close in feature-space might not be close on the grid. the map is similar in concept to the maps produced by descriptive techniques such as multi-dimensional scaling (mds) self-stabilization a property of neural networks (e.g., art models). as a network trains itself on a finite number of cases, the various weights should gradually stabilize. see also: art, ftp:://ftp.sas.com/pub/neural/faq2.html, http://www.wi.leidenuniv.nl/art/.
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Систематическая ошибка отбора, русский
Ошибка, вызванная систематическими различиями характеристик у тех, кто принимает участие в исследовании, и тех, кто в нем не участвует. пример:
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Bia, английский
- Booster impact area
- Booster insertion and abort
- British island airways
- Bureau of indian affairs (u.s.)
- Business impact analysis.
Bia brick institute of america, английский
Американский институт кирпича вк sh book shelves книжные полки
Białoruś, польский
Białorusin (białorusinka), польский
Biały, польский
Biackening, английский
Biadaiolo, итальянский
Biafra, английский
Bial'y, польский
Bialy, английский
Плоская булочка с луком
Bialystok, английский
Г. белосток (польша)
Bianchi, английский
Bianchite, английский
Bianco, итальянский
Bianking, английский
Biaps, английский
Battery inverter accessory power supply
Biard, английский
Biarmicus [a, um], латинский
Biarritz, английский
Г. биарриц (франция)
Biarritzian, английский
Bias, английский
- Current or voltage applied to a circuit to set a reference operating level for proper circuit
- A measurement procedure or estimator is said to be biased if, on the average, it gives an answer that differs from the truth. the bias is the average (expected) difference between the measurement and the truth. for example, if you get on the scale with clothes on, that biases the measurement to be larger than your true weight (this would be a positive bias). the design of an experiment or of a survey can also lead to bias. bias can be deliberate, but it is not necessarily so. see also nonresponse bias.
- A systematic difference or systematic error between an observed value and some measure of the truth. generally used to describe the inaccuracy of a method relative to a comparative method in a method comparison experiment. it also has a specific meaning in the statistical t-test, where bias equals the difference between the mean values of the two methods being compared or the average of all the differences between the paired sample values.
- Battlefield illimination airborne system
- Ошибка случайной выборки, см. distortion; misre- porting; error; deviation
- Current or voltage applied to a circuit to set a reference operating level for proper circuit performance, such as the high frequency bias current applied to an audio recording head to improve linear performance and reduce distortion.
- Предвзятость
- A systematic error in the design or conduct of a study which could explain the results
- Смещение нудя
- Систематическая ошибка отклонение от истины результатов или выводов, или процесс, который ведет к такой ошибке. biologic(al) laboratory, syn. biomedical laboratory
- Систематическая ошибка, смещение. систематическая тенденция, вызванная каким-либо фактором при планировании, выполнении, анализе и оценке результатов клинического исследования. приводит к тому, что оценка эффекта отклоняется от его истинной величины.
- Систематическая ошибка отклонение от истины результатов или выводов, или процесс, который ведет к такой ошибке.
- In tape-recorder electronics, an ultrasonic signal that drives the erase head, and also is mixed with the audio signal applied to the record head to reduce distortion.
- Смещение. разность между математическим ожиданием результата испытания и принятым опорным значением. на смещение могут оказывать влияние один или несколько компонентов систематической ошибки [14]. смещение
- The difference between the estimated value and the true value based
- Неправильная форма кегельного шара, позволяющая ему двигаться не по прямой косая линия в ткани
Systematic, английский
Common to all businesses.
Unconscious, английский
- The unconscious (in psychology) the part of the mind which stores feelings, memories or desires that someone cannot consciously call up. subconscious
- Inconsciente
- Everything that is outside conscious awareness.
Interviewer, английский
- Счетчик (при проведении переписи); лицо, проводящее опрос или собирающее необходимые сведения
- N интервьюер, опрашивающий
- Интервьюер intradermal (intracutaneous) test
- Интервьюер
Individual, английский
Физическое лицо
Eliminated, английский
Устраненный; исключенный
Probability, английский
- Probability can be generally defined as a measure of how likely some event will occur. the event could be an explosion, a lottery win or perhaps cancer induction. mathematically speaking, the value of probability varies between 0 and 1 where 0 means an ev
- Вероятность. возможность.
- The probability of an event is a number between zero and 100%. the meaning (interpretation) of probability is the subject of theories of probability, which differ in their interpretations. however, any rule for assigning probabilities to events has to satisfy the axioms of probability.
- Вероятность
- Вероятность probability sample, syn. random sample
- Вероятность. мера случайности появления конкретного события. например, вероятность случайного выбора из популяции человека с конкретным качеством соответствует доле людей в популяции, обладающих этим качеством.
- Вероятность; возможность
- Вероятность; обеспеченность (гидрологической величины) ~ of no-failure вероятность безотказной работы
- Probability is a method for representing uncertainty about propositions or events. it represents the uncertainty about a proposition on a scale from 0 to 1, with a 0 representing complete certainty that the proposition is false or an event will not occur and a value of one will represent the opposite. formally, a probability measure is one that follows kolmogorov`s axioms. there are two main schools of thought on the meaning of probability. frequentists take a narrow interpretation of probability allowing only hypothetically repeatable events or experiments as being quantifiable by probability, while bayesians take a broader interpretation that allows reasoning about "one-shot" events and propositions based on the current knowledge about nature. the bayesian interpretation is most commonly used in artificial intelligence, while the frequentist interpretation is most commonly taught in statistics courses. the label "bayesian" arises from the central role that the bayes theorem plays in this use of probability. it allows one to reason from effects to causes and encourages the use of probability measures to describe supposedly fixed events or propositions which frequentists disallow. the probability for these events reflects one`s state of knowledge about the event, rather than being an assertion that the unknown event can vary. for example, a bayesian would have no qualms about making statements about the probability that a given die, rolled and hidden from his sight is, for example, a six. a frequentist would be unable to make such a statement, preferring to talk about his confidence in the method when applied to a hypothetically large number of repeated experiments. in the end, they would act in similar ways. when the long run data are available, bayesians and frequentists end up with the same estimates. see also: bayes theorem, kolmogorov`s axioms.
- Вероятность. математическое измерение возможности появления неко-его события, выраженное в виде дроби или процента [30]. значения статистической вероятности лежат в пределах от 1 или 100 процентов (всегда) до 0 или 0 процентов (никогда) [20]. наибольшее приближение к истинной вероятности дает относитель-ная частота события, полученная на основе большой серии измерений или результа-тов [33]. вероятность может быть также определена как выражение в некоторой неопределимой форме "степени уверенности" или как предельная частота события в бесконечной случайной последовательности [49].
- The likelihood of something happening. for example, sale being made.
- Вероятность. математическое измерение возможности появления некоего события, выраженное в виде дроби или процента [30]. значения статистической вероятности лежат в пределах от 1 или 100 процентов (всегда) до 0 или 0 процентов (никогда) [20]. наибольшее приближение к истинной вероятности дает относительная частота события, полученная на основе большой серии измерений или результатов [33]. вероятность может быть также определена как выражение в некоторой неопределимой форме "степени уверенности" или как предельная частота события в бесконечной случайной последовательности [49].
- The relative likelihood of a particular outcome among all possible outcomes.
- Likelihood that an event may occur, expressed as a number between 0 and 1.
Difference, английский
- Disagreement, inequity, contrast, dissimilarity, incompatibility
- Разница; разность
- An important army term, meaning firstly the sum to be paid by officers when exchanging from the half to full pay; and, secondly, the price or difference in value of the several commissions.
Population, английский
- A definable set of individual units to which the findings from statistical examination of a sample subset are intended to be applied. the population will generally much outnumber the sample. in re-randomisation statistics the process of applying inference
- See stock.
- A collection of units being studied. units can be people, places, objects, epochs, drugs, procedures, or many other things. much of statistics is concerned with estimating numerical properties (parameters) of an entire population from a random sample of units from the population.
- A group or number of people living within a specified area or sharing similar characteristics (such as occupation or age).
- Население; народонаселение; генеральная совокупность (в выборочном наблюдении); популяция (биол)
- Население
- 1. the number of people living in a country or town population statistics show that the birth rate is slowing down. the government has decided to screen the whole population of the area. 2. the number of patients in hospital the hospital population in the area has fallen below 10,000.
- Популяция
- Население; популяция -
- Популяция. в клинических исследованиях совокупность субъектов, обладающих какими-либо одинаковыми признаками (пол, возраст, диагноз).
- Население; популяция
- Any group of individuals, usually of a single species, occupying a given area at the same time; groups of organisms with homologue (same) alleles. p. cycle: changes in the numbers of individuals in a population which repeatedly oscillate between periods of high and low density. p. density: allowing a mathematically precise reflection - pd. • absolute: pd = number of individuals/unit area or volume [1/m2] or [1/m3] • relative: pd allows only a simple comparison (pd <, =, >, ? etc.). p. dynamics: the variations in time and space in the sizes and densities of populations; distribution due to changing food resources - the stability of a population depends upon abiotic factors, intraspecific competition (density dependent), natality, mortality etc. p. ecology: the study of the variations in time and space in the sizes and densities of populations, and of the factors causing those variations. p. fluctuation: variations over time in the size of a population. p. growth: is zero, when the birth rate equals the death rate (see carrying capacity). nt+1 = nt + r nt, current number of individuals r = (natality + immigration) - (mortality+emigration) r, intrinsic rate of growth (see density) p. pyramid: a means of illustrating the age structure of a population diagrammatically, by placing the youngest age class at the base and stacking successive age classes above it. p. regulation : a tendency in a population for some factor to cause density to increase when it is low and to decrease nt, momentary number of individuals when it is high. n0, number of individuals at start
- Generally, a collection of individuals with common characteristics. in statistics, a potentially infinite collection of independent (->independence) units that include all units of a specified type with attention paid only to the agggregate (->aggregation) property of the collection. a sample of data drawn from this population is a subset of the units constituting this population and scientific generalizations from such samples are limited by the size of the population originally specified (->model, ->representation).
- The process of scanning content to compile and maintain an index.
- Fish of the same species inhabiting a specified geographic area.
Manufacturer, английский
- (завод-) изготовитель
- Производитель
- Изготовитель; производитель
- Товаропроизводитель
- Birfield transmissions ltd.
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Valid (logical) argument, английский
A valid logical argument is one in which the truth of the premises indeed guarantees the truth of the conclusion. for example, the following logical argument is valid: if the forecast calls for rain, i will not wear sandals. the forecast calls for rain. therefore, i will not wear sandals. this argument has two premises which, together, guarantee the truth of the conclusion. an argument can be logically valid even if its premises are false. see also invalid argument and sound argument.
Systematic random sample, английский
A systematic sample starting at a random point in the listing of units in the of frame, instead of starting at the first unit. systematic random sampling is better than systematic sampling, but typically not as good as simple random sampling.
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