The Wilcoxon signed rank test is applied to compare two populations, when the samples are matched pairs and the data are interval but not normally distributed.

Interval Data

A type of numerical data where the distance between two points is meaningful, including temperatures and dates.

Matched Pairs

An experimental design method where pairs of subjects are matched based on certain criteria to control for confounding variables.

Normally Distributed

Describing a dataset whose distribution of values forms a bell-shaped curve, with most of the values clustering around a central mean value.