Description: The interval scale is a type of measurement scale that allows quantifying variables where the difference between values is significant, but it lacks a true zero point. This means that while arithmetic operations such as addition and subtraction can be performed, multiplication or division involving an absolute zero cannot be done. A classic example of an interval scale is temperature measured in degrees Celsius or Fahrenheit, where the difference between 10 and 20 degrees is the same as between 20 and 30 degrees, but one cannot claim that 20 degrees is twice as hot as 10 degrees. Interval scales are fundamental in statistics and social sciences, as they allow for more precise and meaningful data analysis. The main characteristics of this scale include the uniformity of differences between points and the ability to establish order relationships. However, the absence of a true zero point limits data interpretation, as one cannot speak of the absence of the measured variable. In summary, the interval scale is crucial for data collection and analysis across various disciplines, providing a framework for effectively understanding and comparing variables.
History: The notion of measurement scales was formalized in the 20th century, particularly in the fields of psychology and social sciences. In 1936, American psychologist Stanley Smith Stevens proposed a classification of measurement scales that included nominal, ordinal, interval, and ratio scales. His work laid the groundwork for the systematic use of these scales in research and data analysis.
Uses: Interval scales are used in various disciplines, such as psychology, sociology, and education, to measure variables that do not have an absolute zero. For example, they are used to assess intelligence, where scores can be compared and statistically analyzed. They are also common in temperature studies, where precise analysis of differences between measurements is required.
Examples: An example of an interval scale is temperature measurement in degrees Celsius. In this scale, 0 degrees does not represent the absence of temperature but rather a specific point on the scale. Another example is the intelligence quotient (IQ), where the differences between scores are significant, but there is no absolute zero indicating the absence of intelligence.
