Medianstorlek

Medianstorlek, or median size, is a statistic used to describe the central tendency of a set of measurements that denote size (such as length, diameter, or volume). It is the middle value when the data are ordered from smallest to largest. If the dataset has an odd number of observations, the median is the value at position (n+1)/2. If the dataset has an even number of observations, the median is the average of the two middle values. Unlike the arithmetic mean, the median is less sensitive to extreme values and skewed distributions, making it a robust measure of central tendency for asymmetric data.

In practice, medianstorlek is used to summarize typical sizes in fields such as product design (standardized sizes), biology (body or organ sizes in a population), and housing markets (typical dwelling size). It corresponds to the 50th percentile of the data and is related to other quantiles, such as quartiles and percentiles, which describe different points in the distribution.

Limitations and context: while the median captures central tendency well in skewed data, it does not provide information about the spread or variability of the data. Reporting dispersion measures, such as the interquartile range, is common alongside the median. The median can differ from the mean in skewed distributions; in symmetric distributions they may coincide.

Notes: in Swedish usage, medianstorlek literally means the median of sizes and is employed across statistics, quality control, and empirical research to characterize typical sizes within a dataset.