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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
Slide 9-2Slide 9-2© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-3Slide 9-3© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-4Slide 9-4© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Rule DefinedRule Defined
A rule is a guide, a method, or a command that tells a researcher what to do.
Slide 9-5Slide 9-5© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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
Slide 9-6Slide 9-6© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-7Slide 9-7© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-8Slide 9-8© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-9Slide 9-9© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-10Slide 9-10© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-11Slide 9-11© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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)
Slide 9-12Slide 9-12© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Types of ScalesTypes of ScalesSlide 2 of 8Slide 2 of 8
• 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
Slide 9-13Slide 9-13© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Types of ScalesTypes of ScalesSlide 3 of 8Slide 3 of 8
• 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
Slide 9-14Slide 9-14© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Types of ScalesTypes of ScalesSlide 4 of 8Slide 4 of 8
• 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
Slide 9-15Slide 9-15© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Types of ScalesTypes of ScalesSlide 5 of 8Slide 5 of 8
• 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.
Slide 9-16Slide 9-16© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Types of ScalesTypes of ScalesSlide 6 of 8Slide 6 of 8
• Interval Scale (continued)– Typical Descriptive Statistics
• Mean/variance
– Example of an Interval Scale• Thermometer
Slide 9-17Slide 9-17© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Types of ScalesTypes of ScalesSlide 7 of 8Slide 7 of 8
• 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.
Slide 9-18Slide 9-18© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Types of ScalesTypes of ScalesSlide 8 of 8Slide 8 of 8
• Ratio Scale (continued)– Typical Descriptive Statistics
• Mean.
– Example of a Ratio Scale• Age, weight, height, population of the U.S., etc.
Slide 9-19Slide 9-19© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-20Slide 9-20© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-21Slide 9-21© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-22Slide 9-22© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Assessing the Validity of a Assessing the Validity of a Measurement InstrumentMeasurement Instrument
Slide 1 of 2Slide 1 of 2
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.
Slide 9-23Slide 9-23© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Assessing the Validity of a Assessing the Validity of a Measurement InstrumentMeasurement Instrument
Slide 2 of 2Slide 2 of 2
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.
Slide 9-24Slide 9-24© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
Illustrations of Possible Reliability and Illustrations of Possible Reliability and Validity Situations in MeasurementValidity Situations in Measurement
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Situation 1 Situation 3Situation 2
Neither reliable nor valid
Highly reliable but not valid
Highly reliable and valid
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Slide 9-25Slide 9-25© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-26Slide 9-26© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.
Slide 9-27Slide 9-27© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e© 1999 South-Western Publishing McDaniel Gates Contemporary Marketing Research, 4e
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.