Måleenivå

Måleenivå, often translated as "level of measurement," refers to the type of information a variable or data point represents. Understanding the måleenivå is crucial for selecting appropriate statistical analyses and interpreting results correctly. There are four commonly recognized måleenivå, progressing in their level of sophistication.

The most basic måleenivå is nominal. Nominal data categorizes variables without any inherent order or ranking. Examples include gender (male, female), color (red, blue, green), or marital status (single, married, divorced). These categories are distinct but not comparable in a quantitative sense.

The next level is ordinal. Ordinal data also categorizes variables, but the categories can be ordered or ranked. However, the intervals between these ranks are not necessarily equal or quantifiable. Examples include satisfaction levels (very dissatisfied, dissatisfied, neutral, satisfied, very satisfied) or educational attainment (high school, bachelor's degree, master's degree). We know one category is "more" than another, but not by how much.

Interval data represents a step up in precision. Interval variables have ordered categories with equal and quantifiable intervals between them. However, interval data lacks a true zero point, meaning zero does not represent the absence of the quantity being measured. A classic example is the Celsius or Fahrenheit temperature scale; 0 degrees Celsius does not mean there is no heat.

The highest måleenivå is ratio. Ratio data possesses all the characteristics of interval data, including ordered categories, equal intervals, and a true zero point. The true zero allows for meaningful ratios to be calculated. Examples include height, weight, age, or income. If someone's height is 2 meters, and another's is 1 meter, the first person is twice as tall as the second. This ability to form meaningful ratios is a key distinction of ratio data.