levels of measurement

• Nominal Data

  Simple categories e.g. labelling people as happy or sad based on a questionnaire

  Very basic and least precise - no additional data
• Ordinal Data

  Data which can be placed in order with subjective or unknown intervals e.g. happiness score on a scale of 1 - 10

  More precise than nominal but lacks some precision as measure is subjective
• Interval Data

  Measured using a scale with units of equal size e.g. finger length in cm

  Very precise as it tells you where a score sits