Measurement Scale

Types of Measurement Scale

Nominal Scale

Assign numbers that can be used to identify & classify objects.
Splits data into mutually exclusive categories.

Example: Man-Woman, Left-Right, White-Black

Ordinal Scale

Ranks data in some order.
Attributes are ordered.

Example: Exercising for 20 minutes is good, for 30 minutes is better, for 40 minutes is best.

Interval Scale

Sets data on a continuum.
Distance is meaningful. Differences can be interpreted directly.

Ratio Scale

Starts with absolute zero & indicates proportion.
A value of 0 means that a particular characteristic for a variable is not present.

Properties of Measurement Scale

Note: The interval scale has 1 as an arbitrary starting point. The ratio scale has the natural origin 0, which is meaningful.

Selecting a Test

Important Note:

One of the assumptions of multiple regression & correlation is that IV & DV have a linear relationship. The DV must be continuous & at least interval-scale.