Klassenmarke

Klassenmarke is a statistical term used in German to denote the class mark, the representative value of a class interval in a frequency distribution of grouped data. It is typically the midpoint of the interval and serves as a substitute value for all observations within that class when performing descriptive statistics.

In grouped data analysis, class marks are used to approximate data points and to compute estimates of central tendency and dispersion. For a class interval [a, b) or [a, b], the class mark is usually calculated as (a + b) / 2. For example, the class 10–19 has a class mark of 14.5. When many observations fall within several classes, the overall mean or variance can be estimated by weighting these class marks by the class frequencies.

Klassenmarken are especially important when only aggregated data are available, such as in published tables or summaries, rather than individual values. They enable efficient reconstruction of statistical measures without access to raw data. In German-language texts, the term is often used interchangeably with Klassenmitte or Mittelpunktswert, though some authors may distinguish between subtle notational preferences.

Etymology and usage: the word combines Klasse (class) and Marke (mark). In practice, analysts choose class marks to represent each interval in calculations and graphical representations like histograms or grouped distributions.

See also: Klassenbreite (class width), Klassenmitte/Mittelpunktswert (class midpoint), grouped data analysis.