Slide 9-1 © 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e Understanding Measurement Carl McDaniel, Jr. Roger Gates Slides

Slide 9-1Slide 9-1© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e

Understanding Measurement

Carl McDaniel, Jr.

Roger Gates

Slides Prepared by

Bruce R. Barringer

University of Central Florida

Chapter 9


Learning Objectives

• To understand the concept of measurement.

• To learn about the measurement process and how to develop a good measurement.

• To understand the four levels of scales and their typical usage.

• To become aware of the concepts of reliability and validity.


The Concept of MeasurementThe Concept of Measurement

Measurement is the process of assigning numbers or labels to objects, persons, states, or

events in accordance with specific rules to represent quantities or qualities of attributes.


Rule DefinedRule Defined

A rule is a guide, a method, or a command that tells a researcher what to do.


The Measurement ProcessThe Measurement Process

Identify the concept of

interest

Identify the concept of

interest

Develop a constructDevelop

a construct

a constitutivedefinition

a constitutivedefinition

operationaldefinition

operationaldefinition

measurementscales

measurementscales

evaluate the reliability and the

validity of thescales

evaluate the reliability and the

validity of thescales

utilizes thescales

utilizes thescales

research findingsresearch findings

Use the concept to

Which is used to create

Which enables a researcher to develop an

Which enables a researcher to create

That require the researcher to

If the evaluation is satisfactory, the

researcher

Which leads to


Step One: Identify the Concept of Step One: Identify the Concept of InterestInterest

• Measurement begins by identifying a concept of interest for study.– A concept is an abstract idea generalized from

particular facts.


Step Two: Develop a ConstructStep Two: Develop a Construct

• Constructs are specific types of concepts that exist at higher levels of abstraction.– Constructs are invented for theoretical use.– The value of specific constructs depends on

how useful they are in explaining, predicting, and controlling phenomena, just as the value of everyday concepts depends on how much they assist us in everyday affairs.


Steps Three and Four: Define the Concept Steps Three and Four: Define the Concept Both Constitutively and OperationallyBoth Constitutively and Operationally

Slide 1 of 2Slide 1 of 2 • Constitutive

– A constitutive (or theoretical or conceptual) definition defines a concept with other concepts and constructs, establishing boundaries for the construct under study; it states the central idea or concept under study.


Steps Three and Four: Define the Concept Steps Three and Four: Define the Concept Both Constitutively and OperationallyBoth Constitutively and Operationally

Slide 2 of 2Slide 2 of 2 • Operational Definition

– An operational definition defines which observable characteristics will be measured and the process for assigning a value to the concept.

– In other words, an operational definition serves as a bridge between a theoretical concept and real-world events or factors.


Step Five: Develop a Measurement Step Five: Develop a Measurement ScaleScale

• Scale– A scale is a set of symbols or numbers so

constructed that the symbols or numbers can be assigned by a rule to the individuals (or their behaviors or attitudes) to whom the scale is applied.


Types of ScalesTypes of ScalesSlide 1 of 8Slide 1 of 8

• Nominal Scale– Description

• Uses numerals to identify objects, individuals, events, or groups.

– Basic Empirical Operations• Determination of equality/inequality

– Typical Usage• Classification (male/female; buyer/nonbuyer)



• Nominal Scale (continued)– Typical Descriptive Statistics

• Frequency Counts, percentages/modes

– Example of Nominal Scale• Sex (1) Male (2) Female

• Geographic Area (1) Urban (2) Rural (3) Suburban



• Ordinal Scale– Description

• In addition to identification, the numerals provide information about the relative amount of some characteristic posed by an event, object, etc.

• Basic Empirical Operations

• Determination of greater or less.

– Typical Usage• Rankings/ratings



• Ordinal Scale (continued)– Typical Descriptive Statistics

• Median (mean and variance metric)

– Example of Ordinal Scale:• Please rank the following fax machines from 1 to 5 with 1 being the

most preferred and 5 the least preferred.• _____ Panasonic • _____ Toshiba • _____ Sharp • _____ Savin • _____ Ricoh



• Interval Scale– Description

• Possesses all the properties of nominal and ordinal scales plus the intervals between consecutive points are equal.

– Basic Empirical Operations• Determination of equality of intervals.

– Typical Usage• Preferred measure of complex concepts/constructs.



• Interval Scale (continued)– Typical Descriptive Statistics

• Mean/variance

– Example of an Interval Scale• Thermometer



• Ratio Scale– Description

• Incorporates all the properties of nominal, ordinal, and interval scales plus it includes an absolute zero point.

– Basic Empirical Operations• Determination of equality of ratios.

– Typical Usage• When precision instruments are available.



• Ratio Scale (continued)– Typical Descriptive Statistics

• Mean.

– Example of a Ratio Scale• Age, weight, height, population of the U.S., etc.


Step Six: Evaluate the Reliability Step Six: Evaluate the Reliability and Validity of the Measuresand Validity of the Measures

• Reliability– Is the degree to which measures are free from

random error and, therefore, provide consistent data.

• Validity– Validity addresses the issue of whether what we

try to measure was actually measured.


Assessing the Reliability of a Assessing the Reliability of a Measurement InstrumentMeasurement Instrument

Test-Retest Reliability Use the same instrument a second time

under nearly the same conditions as possible.

Equivalent Form Reliability Use two instruments that are as similar as

possible to measure the same object during

the same time period.

Internal Consistency Compare different samples of items being

Reliability used to measure a phenomenon during the

same time period.


Assessing the Validity of a Assessing the Validity of a Measurement InstrumentMeasurement Instrument

Slide 1 of 2Slide 1 of 2

Face Validity Researchers judge the degree to which a

measurement instrument seems to measure

what it is supposed to.

Content Validity The degree to which the instrument items

represent the universe of the concept under

study.




Criterion-related Validity The degree to which a measurement instrument

can predict a variable that is designed a

criterion.

A. Predictive Validity- The extent to which a

future level of a criterion variable can be

predicted by a current measurement on a

scale.

B. Concurrent Validity- The extent to which

a criterion variable measured at the same

point in time as the variable of interest can

be predicted by the measurement instrument.




Construct Validity The degree to which a measure confirms a

hypothesis created from a theory based upon the

concepts under study.

A. Convergent validity - The degree of

association among different measurement

instruments that purport to measure the same

concept.

B. Discriminant Validity - The lack of

association among constructs that are

supposed to be different.


Illustrations of Possible Reliability and Illustrations of Possible Reliability and Validity Situations in MeasurementValidity Situations in Measurement

.... .....

.

...

. .

.

..

.

.

.

.. .

..

.

Situation 1 Situation 3Situation 2

Neither reliable nor valid

Highly reliable but not valid

Highly reliable and valid

.

..


Summary of Key PointsSummary of Key PointsSlide 1 of 3Slide 1 of 3

• Measurement consists of using rules to assign numbers to objects in such a way as to represent quantities of attributes.

• A measurement rule is a guide, a method, or command that tells the researcher what to do.

• Accurate measurement requires rules that are both clear and specific.


Summary of Key PointsSummary of Key PointsSlide 2 of 3Slide 2 of 3

• The measurement process is as follows: identify the concept of interest, develop a construct, define the concept constitutively and operationally, develop a measurement scale, evaluate the reliability and validity of the scale, and then use the scale.

• There are four basic levels of measurement: nominal, ordinal, interval, and ratio.


SummarySummarySlide 3 of 3Slide 3 of 3

• Measurement data consists of accurate information and errors.

• Reliability is the degree to which measures are free from random error and therefore provide consistent data.

• Validity refers to the notion of actually measuring what we are attempting to measure.

Documents

Slide 9-1 © 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e Understanding Measurement Carl McDaniel, Jr. Roger Gates Slides