In statistics, a frequency distribution is an arrangement of the values that one or more variables take in a sample. Each entry in the table contains the frequency or count of the occurrences of values within a particular group or interval, and in this way, the table summarizes the distribution of values in the sample.
Univariate frequency tables
Univariate frequency distributions are often presented as lists ordered by quantity showing the number of times each value appears. For example, if 100 people rate a five-point Likert scale assessing their agreement with a statement on a scale on which 1 denotes strong agreement and 5 strong disagreement, the frequency distribution of their responses might look like:
Rank Degree of agreement Number 1 Strongly agree 20 2 Agree somewhat 30 3 Not sure 20 4 Disagree somewhat 15 5 Strongly disagree 15
A different tabulation scheme aggregates values into bins such that each bin encompasses a range of values. For example, the heights of the students in a class could be organized into the following frequency table.
Height range Number of students Cumulative number 4.5–5.0 feet 25 25 5.0–5.5 feet 35 60 5.5–6 feet 20 80 6.0–6.5 feet 20 100
A frequency distribution shows us a summarized grouping of data divided into mutually exclusive classes and the number of occurrences in a class. It is a way of showing unorganized data e.g. to show results of an election, income of people for a certain region, sales of a product within a certain period, student loan amounts of graduates, etc. Some of the graphs that can be used with frequency distributions are histograms, line graphs, bar charts and pie charts. Frequency distributions are used for both qualitative and quantitative data.
Joint frequency distributions
Bivariate joint frequency distributions are often presented as (two-way) contingency tables:
Two-way contingency table with marginal frequencies Dance Sports TV Total Men 2 10 8 20 Women 16 6 8 30 Total 18 16 16 50
Managing and operating on frequency tabulated data is much simpler than operation on raw data. There are simple algorithms to calculate median, mean, standard deviation etc. from these tables.
Statistical hypothesis testing is founded on the assessment of differences and similarities between frequency distributions. This assessment involves measures of central tendency or averages, such as the mean and median, and measures of variability or statistical dispersion, such as the standard deviation or variance.
A frequency distribution is said to be skewed when its mean and median are different. The kurtosis of a frequency distribution is the concentration of scores at the mean, or how peaked the distribution appears if depicted graphically—for example, in a histogram. If the distribution is more peaked than the normal distribution it is said to be leptokurtic; if less peaked it is said to be platykurtic.
Letter frequency distributions are also used in frequency analysis to crack codes and are referred to the relative frequency of letters in different languages.
Statistics Descriptive statisticsSummary tablesGrouped data · Frequency distribution · Contingency table Data collectionDesigning studiesUncontrolled studies Statistical inferenceFrequentist inferenceSpecific tests Correlation and regression analysisNon-standard predictorsPartition of variance Categorical, multivariate, time-series, or survival analysis Applications
Wikimedia Foundation. 2010.
Look at other dictionaries:
frequency distribution — n. a numerical tabulation in which the different observed values of a variable, or the different outcomes of an event, are grouped into classes, and the frequencies for each of these classes are given … English World dictionary
Frequency Distribution — A representation, either in a graphical or tabular format, which displays the number of observations within a given interval. The intervals must be mutually exclusive and exhaustive. Frequency distributions are usually used within a statistical… … Investment dictionary
frequency distribution — Statistics. the correspondence of a set of frequencies with the set of categories, intervals, or values into which a population is classified. [1890 95] * * * In statistics, a graph or data set organized to show the frequency of occurrence of… … Universalium
frequency distribution — dažninis skirstinys statusas T sritis Standartizacija ir metrologija apibrėžtis Skirstinys, išreiškiantis sąsają tarp išmatuotų kintamojo dydžio verčių ir jų pasirodymo dažnio. atitikmenys: angl. frequency distribution vok. Frequenzverteilung, f; … Penkiakalbis aiškinamasis metrologijos terminų žodynas
frequency distribution — dažnių pasiskirstymas statusas T sritis fizika atitikmenys: angl. frequency distribution vok. Frequenzverteilung, f rus. распределение по частотам, n; частотное распределение, n pranc. distribution des fréquences, f … Fizikos terminų žodynas
frequency distribution — dažninis skirstinys statusas T sritis fizika atitikmenys: angl. frequency distribution vok. Häufigkeitsverteilung, f rus. частотное распределение, n pranc. distribution de fréquence, f … Fizikos terminų žodynas
frequency distribution — (in statistics) presentation of the characteristics (variable) of a series of individuals (e.g. their heights, weights, or blood pressures) in tabular form or as a histogram (bar chart) so as to indicate the proportion of the series that have… … Medical dictionary
frequency distribution — (in statistics) presentation of the characteristics (variables) of a series of individuals (e.g. their heights, weights, or blood pressures) in tabular form or as a histogram (bar chart) so as to indicate the proportion of the series that have… … The new mediacal dictionary
frequency distribution — noun a distribution of observed frequencies of occurrence of the values of a variable • Topics: ↑statistics • Hypernyms: ↑distribution, ↑statistical distribution … Useful english dictionary
frequency distribution — noun Date: 1895 an arrangement of statistical data that exhibits the frequency of the occurrence of the values of a variable … New Collegiate Dictionary