Mõõtmeliike

Mõõtmeliike refers to different scales or levels of measurement used in statistics and research. Understanding these measurement scales is crucial for choosing appropriate statistical analyses and interpreting data correctly. The four primary types of measurement scales are nominal, ordinal, interval, and ratio.

Nominal scales are used for categorical data where categories have no inherent order or ranking. Examples include classifying people by gender, marital status, or color. The only operation that can be performed on nominal data is counting the frequency of each category.

Ordinal scales are also used for categorical data, but the categories have a meaningful order or ranking. However, the differences between the ranks are not necessarily equal or quantifiable. Examples include survey responses like "strongly agree," "agree," "neutral," "disagree," and "strongly disagree," or ranking students from best to worst.

Interval scales have ordered categories with equal and quantifiable differences between them, but they lack a true zero point. A true zero point means the complete absence of the quantity being measured. Temperature in Celsius or Fahrenheit is a common example of interval data. While 0 degrees Celsius exists, it doesn't mean the absence of temperature; it's just a point on the scale.

Ratio scales possess all the properties of interval scales (ordered categories, equal intervals) and also have a true zero point. This true zero allows for meaningful ratios between values. Examples include height, weight, age, and income. If someone has zero height, they are absent; if one person is twice as tall as another, the ratio is meaningful. The choice of measurement scale dictates the types of statistical tests that can be applied, influencing how data is analyzed and conclusions are drawn.