[data structures]
A method of organizing data values into a ranked hierarchy with no fixed interval between the hierarchical levels. A common example of ordinal data is a Likert scale, which assigns a numeric value on an ordinal scale to questionnaire responses such as "Agree", "Somewhat agree", "Neutral", "Somewhat disagree", and "Disagree". A group of polygons colored lighter to darker to represent less to more densely populated areas is an example of ordinal data in GIS.