##
alternative hypothesis

Overview page. Subjects: Psychology — Probability and Statistics.

The hypothesis, in a hypothesis test, that will be accepted if the null hypothesis is rejected. The term was introduced by Neyman and Egon Pearson in 1933.

##
decile

Overview page. Subjects: Psychology — Probability and Statistics.

An approximate value for the *r*th decile of a data set can be read from a cumulative frequency graph as the value of the variable corresponding to a cumulative relative frequency of 10*r*%. So...

##
Fisher exact test

Overview page. Subjects: Probability and Statistics — Psychology.

A statistical test used to examine the significance of the association between two categorical variables in a 2×2 contingency table. The test needs the expected values in each cell to be at...

##
five-number summary

Overview page. Subjects: Psychology — Probability and Statistics.

For a set of numerical data, the least value, the lower quartile, the median, the upper quartile, and the greatest value, in that order. See boxplot.

##
interval scale

Overview page. Subjects: Psychology — Probability and Statistics.

A scale of measurement in which differences between values can be quantified in absolute terms but the zero point is fixed arbitrarily, familiar examples being Fahrenheit or Celsius...

##
Kendall's tau

Overview page. Subjects: Probability and Statistics — Psychology.

In statistics, an index of the degree of association between two variables measured on an ordinal scale or transformed to ranks. Its computation involves examining every pair of items and...

##
Kruskal–Wallis test

Overview page. Subjects: Probability and Statistics — Psychology.

A non-parametric test for comparisons between more than two medians, using the relative rankings within the different samples.

##
Louis Leon Thurstone

Overview page. Subjects: Probability and Statistics — Psychology.

(1887–1955; b. Chicago, IL; d. Chapel Hill, TN)

American psychometrician. Thurstone graduated from Cornell U with a BS in electrical engineering in 1912. This led to employment...

##
McNemar test

Overview page. Subjects: Probability and Statistics — Psychology.

In statistics, a distribution-free test of the significance of changes, especially applicable to before-after designs of the effects of particular treatments in which scores are dichotomous...

##
Rasch model

Overview page. Subjects: Psychology — Probability and Statistics.

A simple model that describes the probability that, when a group of individuals are asked a number of questions, individual *j* makes a mistake in answering question *k*. The model, which was...