| geometric mean | - The geometric mean of n numbers {x1, x2, x3, …, xn} is the nth root of their product:
- Среднее геометрическое (значение, величина)
- Средняя геометрическая (величина) усредн...
gm; средняя геометрическая; геометрическое среднее; |
| hypergeometric distribution | - The hypergeometric distribution with parameters n, g and n is the distribution of the number of "good" objects in a simple random sample of size n (i.e., a random sample without replacement in...
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| indicator random variable | The indicator [random variable] of the event a, often written 1a, is the random variable that equals unity if a occurs, and zero if a does not occur. the expected value of the indicator of a is th... |
| treatment group | The individuals who receive the treatment, as opposed to those in the control group, who do not. |
| inter-quartile range (iqr) | The inter-quartile range of a list of numbers is the upper quartile minus the lower quartile. |
| law of averages | The law of averages says that the average of independent observations of random variables that have the same probability distribution is increasingly likely to be close to the expected value of th... |
| law of large numbers | - The law of large numbers says that in repeated, independent trials with the same probability p of success in each trial, the percentage of successes is increasingly likely to be close to the c...
закон больших чисел; |
| marginal probability distribution | The marginal probability distribution of a random variable that has a joint probability distribution with some other random variables is the probability distribution of that random variable withou... |
| maximum likelihood estimate (mle) | The maximum likelihood estimate of a parameter from data is the possible value of the parameter for which the chance of observing the data largest. that is, suppose that the parameter is p, and th... |
| population mean | - The mean of the numbers in a numerical population. for example, the population mean of a box of numbered tickets is the mean of the list comprised of all the numbers on all the tickets. the po...
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| mean squared error (mse) | The mean squared error of an estimator of a parameter is the expected value of the square of the difference between the estimator and the parameter. in symbols, if x is an estimator of the paramet... |
| method of comparison | The most basic and important method of determining whether a treatment has an effect: compare what happens to individuals who are treated (the treatment group) with what happens to individuals who... метод сравнения; |
| bootstrap estimate of standard error | The name for this idea comes from the idiom "to pull oneself up by one`s bootstraps," which connotes getting out of a hole without anything to stand on. the idea of the bootstrap is to assume, for... |
| not, , negation, logical negation | The negation of a logical proposition p, !p, is a proposition that is the logical opposite of p. that is, if p is true, !p is false, and if p is false, !p is true. negation takes precedence over o... |
| normal approximation | The normal approximation to data is to approximate areas under the histogram of data, transformed into standard units, by the corresponding areas under the normal curve. |
| outcome space | The outcome space is the set of all possible outcomes of a given random experiment. the outcome space is often denoted by the capital letter s. |
| sample percentage | The percentage of a random sample with a certain property, such as the percentage of voters registered as democrats in a simple random sample of voters. the sample mean is a statistic commonly use... |
| population percentage | The percentage of units in a population that possess a specified property. for example, the percentage of a given collection of registered voters who are registered as republicans. if each unit th... |
| probability distribution | - The probability distribution of a random variable specifies the chance that the variable takes a value in any subset of the real numbers. (the subsets have to satisfy some technical conditions...
распределение вероятностей; |
| symmetric distribution | The probability distribution of a random variable x is symmetric if there is a number a such that the chance that x≥a+b is the same as the chance that x≤a−b for every value of b.... |
| complement rule | The probability of the complement of an event is 100% minus the probability of the event: p(ac) = 100% − p(a). |
| prosecutor`s fallacy | The prosecutor`s fallacy consists of confusing two conditional probabilities: p(a|b) and p(b|a). for instance, p(a|b) could be the chance of observing the evidence if the accused is guilty, while ... |
| regression fallacy | The regression fallacy is to attribute the regression effect to an external cause. |
| nonlinear association | The relationship between two variables is nonlinear if a change in one is associated with a change in the other that is depends on the value of the first; that is, if the change in the second is n... |
| root-mean-square (rms) | The rms of a list is the square-root of the mean of the squares of the elements in the list. it is a measure of the average "size" of the elements of the list. to compute the rms of a list, you sq... |
| root-mean-square error (rmse) | The rmse of an an estimator of a parameter is the square-root of the mean squared error (mse) of the estimator. in symbols, if x is an estimator of the parameter t, then |
| sample standard deviation, s | The sample standard deviation s is an estimator of the standard deviation of a population based on a random sample from the population. the sample standard deviation is a statistic that measures h... |
| sampling distribution | The sampling distribution of an estimator is the probability distribution of the estimator when it is applied to random samples. the tool on this page allows you to explore empirically the samplin... |
| scientific method | - The scientific method….
- Principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through obse...
научный метод; |
| significance, significance level, statistical significance | The significance level of an hypothesis test is the chance that the test erroneously rejects the null hypothesis when the null hypothesis is true. |
| square-root law | The square-root law says that the standard error (se) of the sample sum of n random draws with replacement from a box of tickets with numbers on them is |
| standard deviation (sd) | - The standard deviation of a set of numbers is the rms of the set of deviations between each element of the set and the mean of the set. see also sample standard deviation.
- Стандартн...
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| population standard deviation | The standard deviation of the values of a variable for a population. this is a parameter, not a statistic. c.f. sample standard deviation. |
| standard error (se) | The standard error of a random variable is a measure of how far it is likely to be from its expected value; that is, its scatter in repeated experiments. the se of a random variable x is defined t... |
| control group | - The subjects in a controlled experiment who do not receive the treatment.
- A group of people who are not being treated but whose test data are used as a comparison in a study
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cg; контрольная группа; |
| mean, arithmetic mean | The sum of a list of numbers, divided by the number of numbers. see also average. |
| sample sum | The sum of a random sample from a population. the expected value of the sample sum is the sample size times the population mean. for sampling with replacement, the se of the sample sum is the popu... |
| density, density scale | The vertical axis of a histogram has units of percent per unit of the horizontal axis. this is called a density scale; it measures how "dense" the observations are in each bin. see also probabilit... |
| axioms of probability | There are three axioms of probability: (1) chances are always at least zero. (2) the chance that something happens is 100%. (3) if two events cannot both occur at the same time (if they are disjoi... |
| type i and type ii errors | - These refer to hypothesis testing. a type i error occurs when the null hypothesis is rejected erroneously when it is in fact true. a type ii error occurs if the null hypothesis is not rejected...
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| control for a variable | To control for a variable is to try to separate its effect from the treatment effect, so it will not confound with the treatment. there are many methods that try to control for variables. some are... |
| independent, independence | Two events a and b are (statistically) independent if the chance that they both happen simultaneously is the product of the chances that each occurs individually; i.e., if p(ab) = p(a)p(b). this i... |
| disjoint or mutually exclusive events | Two events are disjoint or mutually exclusive if the occurrence of one is incompatible with the occurrence of the other; that is, if they can`t both happen at once (if they have no outcome in comm... |
| dependent events, dependent random variables | Two events or random variables are dependent if they are not independent. |
| logically equivalent, logical equivalence | Two propositions are logically equivalent if they always have the same truth value. that is, the propositions p and q are logically equivalent if p is true whenever q is true and p is false whenev... |
| disjoint or mutually exclusive sets | Two sets are disjoint or mutually exclusive if they have no element in common. equivalently, two sets are disjoint if their intersection is the empty set. |
| causation, causal relation | Two variables are causally related if changes in the value of one cause the other to change. for example, if one heats a rigid container filled with a gas, that causes the pressure of the gas in t... |
| linear association | Two variables are linearly associated if a change in one is associated with a proportional change in the other, with the same constant of proportionality throughout the range of measurement. the c... |
| simpson`s paradox | What is true for the parts is not necessarily true for the whole. see also confounding. парадокс симпсона; |
| finite population correction | When sampling without replacement, as in a simple random sample, the se of sample sums and sample means depends on the fraction of the population that is in the sample: the greater the fraction, t... |
| xor, exclusive disjunction | Xor is an operation on two logical propositions. if p and q are two propositions, (p xor q) is a proposition that is true if either p is true or if q is true, but not both. (p xor q) is logically ... |
