målingstype

A målingstype, or measurement type, refers to the nature of the data collected by a measuring instrument or method. It dictates how the data can be analyzed and interpreted. Understanding the målingstype is crucial for selecting appropriate statistical methods and drawing valid conclusions.

There are generally four primary målingstyper, often presented in a hierarchical order of increasing information content: nominal, ordinal, interval, and ratio. Nominal data, the simplest type, categorizes data without any inherent order. Examples include gender, color, or types of cars. Ordinal data also categorizes but includes a meaningful order or rank. Examples include survey responses like "poor," "fair," "good," or finishing positions in a race.

Interval data possesses both order and equal intervals between values, but lacks a true zero point. Temperature in Celsius or Fahrenheit is a classic example; the difference between 10 and 20 degrees is the same as the difference between 30 and 40 degrees, but 0 degrees does not signify the complete absence of temperature. Ratio data is the most informative type, featuring order, equal intervals, and a true zero point. Height, weight, and income are ratio variables. A height of 0 meters means no height, and a person twice as tall as another is indeed twice their height. The distinction between these målingstyper guides the choice of statistical tests, as certain operations are only valid for specific types of data.