levels of measurement

• Nominal


  The level of measurement that shows categories of data represented by frequencies. The data sets have no relative numerical value, e.g. boys and girls.
• Ordinal


  The level of measurement where data can be placed into ascending or descending order, but the intervals between data are not necessarily equal, e.g. the times for first, second and third in a race.
• Interval


  The level of measurement that has equal numerical intervals between scores, e.g. temperature. The interval between 1 and 2 degrees is the same as between 21 and 22 degrees.
• Ratio


  The level of measurement that has equal intervals between scores and has an absolute or true zero point, e.g. speed (mph).
• Levels of measurement

  • They signify both the type of data that has been collected and how sophisticated/complex the data is
  • We need to know the level of measurement so that we can correctly identify an appropriate statistical test and draw conclusions about differences across the data set accordingly
• The main difference between the levels of measurement is how sophisticated or detailed each measure is
• Levels of measurement from least to most sophisticated

  • Nominal
  • Ordinal
  • Interval
  • Ratio