| applet | - An applet is a small program that is automatically downloaded from a website to your computer when you visit a particular web page; it allows a page to be interactive—to respond to your input....
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| certain event | - An event is certain if its probability is 100%. even if an event is certain, it might not occur. however, by the complement rule, the chance that it does not occur is 0%.
- Достоверно...
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| randomized controlled experiment | An experiment in which chance is deliberately introduced in assigning subjects to the treatment and control groups. for example, we could write an identifying number for each subject on a slip of ... |
| uncontrolled experiment | An experiment in which there is no control group; i.e., in which the method of comparison is not used: the experimenter decides who gets the treatment, but the outcome of the treated group is not ... |
| controlled experiment | An experiment that uses the method of comparison to evaluate the effect of a treatment by comparing treated subjects with a control group, who do not receive the treatment. |
| t test | An hypothesis test based on approximating the probability histogram of the test statistic by student`s t curve. t tests usually are used to test hypotheses about the mean of a population when the ... |
| invalid (logical) argument | An invalid logical argument is one in which the truth of the premises does not guarantee the truth of the conclusion. for example, the following logical argument is invalid: if the forecast calls ... |
| and, &, conjunction, logical conjunction, ∧ | An operation on two logical propositions. if p and q are two propositions, (p & q) is a proposition that is true if both p and q are true; otherwise, (p & q) is false. the operation & is sometimes... |
| bayes` rule | Bayes` rule expresses the conditional probability of the event a given the event b in terms of the conditional probability of the event b given the event a and the unconditional probability of a:<... |
| observational study | - C.f. controlled experiment.
- A type of scientific study that involves measurement of study subjects on variables hypothesized to be associated with the outcome of interest, but witho...
исследование обсервационное; наблюдательное исследование; |
| two-sided hypothesis test | C.f. one-sided test. an hypothesis test of the null hypothesis that the value of a parameter, μ, is equal to a null value, μ0, designed to have power against the alternative hypothesis t... |
| one-sided test | C.f. two-sided test. an hypothesis test of the null hypothesis that the value of a parameter, μ, is equal to a null value, μ0, designed to have power against either the alternative hypot... |
| negative binomial distribution | Consider a sequence of independent trials with the same probability p of success in each trial. the number of trials up to and including the rth success has the negative binomial distribution with... |
| fisher`s exact test (for the equality of two percentages) | Consider two populations of zeros and ones. let p1 be the proportion of ones in the first population, and let p2 be the proportion of ones in the second population. we would like to test the null ... |
| de morgan`s laws | De morgan`s laws are identities involving logical operations: the negation of a conjunction is logically equivalent to the disjunction of the negations, and the negation of a disjunction is logica... |
| sd line | For a scatterplot, a line that goes through the point of averages, with slope equal to the ratio of the standard deviations of the two plotted variables. if the variable plotted on the horizontal ... |
| graph of averages | For bivariate data, a graph of averages is a plot of the average values of one variable (say y) for small ranges of values of the other variable (say x), against the value of the second variable (... |
| chebychev`s inequality | For lists: for every number k>0, the fraction of elements in a list that are k sd`s or further from the arithmetic mean of the list is at most 1/k2. |
| markov`s inequality | For lists: if a list contains no negative numbers, the fraction of numbers in the list at least as large as any given constant a>0 is no larger than the arithmetic mean of the list, divided by a.<... |
| unimodal | Having exactly one mode. унимодальный; |
| fundamental rule of counting | If a sequence of experiments or trials t1, t2, t3, …, tk could result, respectively, in n1, n2 n3, …, nk possible outcomes, and the numbers n1, n2 n3, …, nk do not depend on which outcomes actuall... |
| contrapositive | - If p and q are two logical propositions, then the contrapositive of the proposition (p → q) is the proposition ((! q) → (!p) ). the contrapositive is logically equivalent to the or...
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| joint probability distribution | If x1, x2, … , xk are random variables defined for the same experiment, their joint probability distribution gives the probability of events determined by the collection of random variables: for a... |
| blind, blind experiment | In a blind experiment, the subjects do not know whether they are in the treatment group or the control group. in order to have a blind experiment with human subjects, it is usually necessary to ad... |
| cluster sample | - In a cluster sample, the sampling unit is a collection of population units, not single population units. for example, techniques for adjusting the u.s. census start with a sample of geographic...
выборка; |
| consequent | - In a conditional p → q, the consequent is q.
- N второй член услов- ного предложения, следствие
- Следствие;консеквент
консеквентный; |
| double-blind, double-blind experiment | In a double-blind experiment, neither the subjects nor the people evaluating the subjects knows who is in the treatment group and who is in the control group. this mitigates the placebo effect and... |
| football-shaped scatterplot | In a football-shaped scatterplot, most of the points lie within a tilted oval, shaped more-or-less like a football. a football-shaped scatterplot is one in which the data are homoscedastically sca... |
| point of averages | In a scatterplot, the point whose coordinates are the arithmetic means of the corresponding variables. for example, if the variable x is plotted on the horizontal axis and the variable y is plotte... |
| stratified sample | In a stratified sample, subsets of sampling units are selected separately from different strata, rather than from the frame as a whole. |
| nonresponse bias | In a survey, those who respond may differ from those who do not, in ways that are related to the effect one is trying to measure. for example, a telephone survey of how many hours people work is l... |
| rejection region | In an hypothesis test using a test statistic, the rejection region is the set of values of the test statistic for which we reject the null hypothesis. |
| house edge | In casino games, the expected payoff to the bettor is negative: the house (casino) tends to win money in the long run. the amount of money the house would expect to win for each $1 wagered on a pa... |
| minimax strategy | - In game theory, a minimax strategy is one that minimizes one`s maximum loss, whatever the opponent might do (whatever strategy the opponent might choose).
- Стратегия минимакс
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| alternative hypothesis | - In hypothesis testing, a null hypothesis (typically that there is no effect) is compared with an alternative hypothesis (typically that there is an effect, or that there is an effect of a part...
альтернативная гипотеза; |
| multiplicity in hypothesis tests | In hypothesis testing, if more than one hypothesis is tested, the actual significance level of the combined tests is not equal to the nominal significance level of the individual tests. see also f... |
| endpoint convention | In plotting a histogram, one must decide whether to include a datum that lies at a class boundary with the class interval to the left or the right of the boundary. the rule for making this assignm... |
| explanatory variable | - In regression, the explanatory or independent variable is the one that is supposed to "explain" the other. for example, in examining crop yield versus quantity of fertilizer applied, the quant...
переменная объяснительная; |
| independent variable | - In regression, the independent variable is the one that is supposed to explain the other; the term is a synonym for "explanatory variable." usually, one regresses the "dependent variable" on t...
переменная независимая; |
| dependent variable | - In regression, the variable whose values are supposed to be explained by changes in the other variable (the the independent or explanatory variable). usually one regresses the dependent variab...
переменная зависимая; |
| nonresponse | In surveys, it is rare that everyone who is ``invited`` to participate (everyone whose phone number is called, everyone who is mailed a questionnaire, everyone an interviewer tries to stop on the ... |
| false discovery rate | In testing a collection of hypotheses, the false discovery rate is the fraction of rejected null hypotheses that are rejected erroneously (the number of type i errors divided by the number of reje... |
| continuity correction | In using the normal approximation to the binomial probability histogram, one can get more accurate answers by finding the area under the normal curve corresponding to half-integers, transformed to... |
| principle of insufficient reason (laplace) | Laplace`s principle of insufficient reason says that if there is no reason to believe that the possible outcomes of an experiment are not equally likely, one should assume that the outcomes are eq... |
| regression, linear regression | Linear regression fits a line to a scatterplot in such a way as to minimize the sum of the squares of the residuals. the resulting regression line, together with the standard deviations of the two... |
| real number | - Loosely speaking, the real numbers are all numbers that can be represented as fractions (rational numbers), whether proper or improper—and all numbers in between the rational numbers. that is,...
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| self-selection | - Self-selection occurs when individuals decide for themselves whether they are in the control group or the treatment group. self-selection is quite common in studies of human behavior. for exam...
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| member of a set | Something is a member (or element) of a set if it is one of the things in the set. |
| historical controls | Sometimes, the a treatment group is compared with individuals from another epoch who did not receive the treatment; for example, in studying the possible effect of fluoridated water on childhood c... |
| hypothesis testing | - Statistical hypothesis testing is formalized as making a decision between rejecting or not rejecting a null hypothesis, on the basis of a set of observations. two types of errors can result fr...
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| fpp | - Statistics, third edition, by freedman, pisani, and purves, published by w.w. norton, 1997.
- Flight proof plan
- From present position
- Fossil power plant
<...
flight proof plan; from present position; |
| student`s t curve | Student`s t curve is a family of curves indexed by a parameter called the degrees of freedom, which can take the values 1, 2, … student`s t curve is used to approximate some probability histograms... |
| linear operation | Suppose f is a function or operation that acts on things we shall denote generically by the lower-case roman letters x and y. suppose it makes sense to multiply x and y by numbers (which we denote... |
| regression toward the mean, regression effect | Suppose one measures two variables for each member of a group of individuals, and that the correlation coefficient of the variables is positive (negative). if the value of the first variable for t... |
| conditional probability | - Suppose we are interested in the probability that some event a occurs, and we learn that the event b occurred. how should we update the probability of a to reflect this new knowledge? this is ...
вероятность условная; |
| sample mean | The arithmetic mean of a random sample from a population. it is a statistic commonly used to estimate the population mean. suppose there are n data, {x1, x2, … , xn}. the sample mean is (x1 + x2 +... |
| base rate fallacy | The base rate fallacy consists of failing to take into account prior probabilities (base rates) when computing conditional probabilities from other conditional probabilities. it is related to the ... |
| placebo effect | - The belief or knowledge that one is being treated can itself have an effect that confounds with the real effect of the treatment. subjects given a placebo as a pain-killer report statistically...
плацебо эффект; |
| bernoulli`s inequality | The bernoulli inequality says that if x ≥ −1 then (1+x)n ≥ 1 + nx for every integer n ≥ 0. if n is even, the inequality holds for all x. |
| binomial theorem | The binomial theorem says that (x+y)n = xn + nxn−1y + … + nckxn−kyk + … + yn. |
| htlws | The book how to lie with statistics by d. huff. |
| breakdown point | The breakdown point of an estimator is the smallest fraction of observations one must corrupt to make the estimator take any value one wants. |
| central limit theorem | - The central limit theorem states that the probability histograms of the sample mean and sample sum of n draws with replacement from a box of labeled tickets converge to a normal curve as the s...
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| multiplication rule | The chance that events a and b both occur (i.e., that event ab occurs), is the conditional probability that a occurs given that b occurs, times the unconditional probability that b occurs. |
| chi-square curve | The chi-square curve is a family of curves that depend on a parameter called degrees of freedom (d.f.). the chi-square curve is an approximation to the probability histogram of the chi-square stat... |
| chi-square statistic | The chi-square statistic is used to measure the agreement between categorical data and a multinomial model that predicts the relative frequency of outcomes in each possible category. suppose there... |
| ecological correlation | The correlation between averages of groups of individuals, instead of individuals. ecological correlation can be misleading about the association of individuals. экологическая корреляция; |
| correlation coefficient | - The correlation coefficient r is a measure of how nearly a scatterplot falls on a straight line. the correlation coefficient is always between −1 and +1. to compute the correlation coeff...
корреляции коэффициент; |
| coverage probability | The coverage probability of a procedure for making confidence intervals is the chance that the procedure produces an interval that covers the truth. |
| cumulative probability distribution function (cdf) | The cumulative distribution function of a random variable is the chance that the random variable is less than or equal to x, as a function of x. in symbols, if f is the cdf of the random variable ... |
| treatment effect | - The effect of the treatment on the variable of interest. establishing whether the treatment has an effect is the point of an experiment.
- Эффект лечения. заключение о результате прим...
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| distribution function, empirical | The empirical (cumulative) distribution function of a set of numerical data is, for each real value of x, the fraction of observations that are less than or equal to x. a plot of the empirical dis... |
| empirical law of averages | The empirical law of averages lies at the base of the frequency theory of probability. this law, which is, in fact, an assumption about how the world works, rather than a mathematical or physical ... |
| empty set | - The empty set, denoted {} or o, is the set that has no members.
- Пустое множество
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| expectation, expected value | The expected value of a random variable is the long-term limiting average of its values in independent repeated experiments. the expected value of the random variable x is denoted ex or e(x). for ... |
| nonresponse rate | The fraction of nonresponders in a survey: the number of nonresponders divided by the number of people invited to participate (the number sent questionnaires, the number of interview attempts, etc... |
| geometric distribution | The geometric distribution describes the number of trials up to and including the first success, in independent trials with the same probability of success. the geometric distribution depends only... |
