Stats- Measurement Scales

Equal Intervals

Scale units along the scale are equal to one another. This means, for example, that the difference between 1 and 2 would be the equal to the difference of 19 and 20

Interval Scale of Measurment

The interval scale of measurement has the properties of identity, magnitude, and equal intervals. A perfect example of an interval scale is the Fahrenheit scale to measure temperature. The scale is made up of equal temperature units, so that the difference between 40 and 50 degrees Fahrenheit is equal to the difference between 50 and 60 degrees Fahrenheit.

Ordinal Scale of Measurement

The ordinal scale has the property of both identity and magnitude. Each value on the ordinal scale has a unique meaning, and it has an ordered relationship to every other value on the scale. An example of an ordinal scale in action would be the results of a horse race, reported as "win", "place", and "show".

A Minimum Value of zero

The scale has a true zero point, below which no value exists.

Magnitude

values on a measurement scale have an ordered relationship to one another. That is, some values are larger and some are smaller

Nominal Scale of Measurement

Only satisfies the identity part of measurement. Values assigned to variables represent a descriptive category, but have no inherent numerical value with respect to magnitude. Gender is an example of a variable that is measured on a nominal scale. Individuals may be classified as "male" or "female", but neither value represents more or less "gender" than the other. Religion and political affiliation are other examples of variables that are normally measured on a nominal scale.

Ratio Scale of Measurement

The ratio scale of measurement satisfies all four of the properties of measurement: identity, magnitude, equal intervals, and a minimum value of zero. The weight of an object would be an example of a ratio scale. Each value on the weight scale has a unique meaning, weights can be rank ordered, units along the weight scale are equal to one another, and the scale has a minimum value of zero. Weight scales have a minimum value of zero because objects at rest can be weightless, but they cannot have negative weight.

Identity

each value on the measurement scale has unique meaning