SCALE MEASUREMENT

By: CRAG, D.A.E.

used to categorize and/or quantify variables.

procedure for the assignment of numbers in order to impart some of the characteristics in relation to the question (being surveyed).

SCALE MEASUREMENT

ways in which variables/numbers are defined and categorized.

determines the appropriateness for use of certain statistical analyses.

SCALE MEASUREMENT

Assignment Order Distance Origin

FOUR BASIC SCALING PROPERTIES

Nominal Ordinal Interval Ratio

FOUR SCALES OF MEASUREMENT

Lowest form of measurement Provide least number of data Only satisfies the identity property of measurement

NOMINAL

NOMINAL

Represents an ordered series of relationships or rank order.

Each value has a unique meaning, and it has an ordered relationship to every other value on the scale.

ORDINAL

ORDINAL

numeric scales in which we know not only the order, but also the exact differences between the values.

measurement has the properties of identity, magnitude, and equal intervals.

INTERVAL

INTERVAL

similar to the interval scale, it also represents quantity and has equality of units

RATIO

Tell the exact unit (has an absolute zero point)

Contains all of the information of the previous 3 leves

RATIO

NOMINAL variables are used to “name,” or label a series of values.

ORDINAL scales provide good information about the order of choices, such as in a customer satisfaction survey.

SUMMARY

INTERVAL scales give us the order of values + the ability to quantify the difference between each one.

RATIO scales give us the ultimate–order, interval values, plus the ability to calculate ratios since a “true zero” can be defined.

SUMMARY

MAKE SURE you consider carefully the level at which you collect your data.

REMINDER

ENDThank you for listening