Interval measurement is a level of measurement in which the intervals between the values on a scale are equal, but the scale does not have a true zero point. This means that the values on the scale can be compared and ranked, but the difference between two values cannot be interpreted as a true difference in quantity.
An example of an interval scale is the Fahrenheit temperature scale, which is used to measure temperature in the United States. On the Fahrenheit scale, the intervals between the values (degrees) are equal, but the scale does not have a true zero point. This means that the difference between 20 degrees and 30 degrees is the same as the difference between 80 degrees and 90 degrees, but it does not mean that 20 degrees is twice as cold as 10 degrees.
Interval measurement is one of four levels of measurement in quantitative research, along with nominal, ordinal, and ratio. Each level of measurement has its own characteristics and limitations, and it is important to choose the appropriate level of measurement for your research question and data.
