Skalenivåerna

Skalenivåerna, often translated as measurement scales or levels of measurement, refer to the classification of data based on the properties of the numbers assigned to them. These scales dictate the types of mathematical operations that can be performed on the data and the conclusions that can be drawn.

The four main skalenivåerna are nominal, ordinal, interval, and ratio. Nominal scales are the simplest, used for categorical data where numbers serve only as labels or names. Examples include gender (1=male, 2=female) or types of fruit. Only basic counting and frequency analysis are possible.

Ordinal scales are used for data that can be ranked or ordered, but the differences between the ranks are not necessarily equal or quantifiable. Examples include survey responses like "disagree," "neutral," and "agree," or finishing positions in a race (1st, 2nd, 3rd). We can determine order, but not the exact magnitude of differences.

Interval scales involve data where the order matters and the differences between consecutive values are equal and meaningful. However, there is no true zero point, meaning zero does not represent the absence of the measured quantity. Temperature in Celsius or Fahrenheit are common examples; a temperature of 0°C does not mean the absence of heat. Addition and subtraction are permissible, but multiplication and division are not always meaningful.

Ratio scales are the most informative. They have all the properties of interval scales, including equal intervals, plus a true zero point. This true zero signifies the complete absence of the quantity being measured. Examples include height, weight, and income. With ratio scales, all mathematical operations, including multiplication and division, are meaningful. For instance, a height of 2 meters is twice as tall as a height of 1 meter. Understanding these skalenivåerna is crucial for appropriate statistical analysis and interpretation of research findings.