All groups are discrete. There is both no overlap between classifications and no intermediary values . Characteristics are the same as for nominal data except that there is some order to the classification. In this case improved is greater than same. For example the number of anaesthetics administered in the Royal Brisbane Hospital in 1994.
Values have both order and meaningful value.
However often this data type is not normally distributed. Furthermore intermediate values have no meaning. For example age, temperature, metabolic rate. A scale in which intermediate values have meaning and a mathematical relationship exists between values. The normal distribution A frequency histogram of the result obtained from repetitive measurements made of biological variables frequently follows a characteristic shape likened to that of an upside down bell - The Normal Distribution.