Collecting Data by Communication Chapter 12. Measurement “rules for assigning numbers to objects in such a way as to represent quantities of attributes”

Collecting Data by Communication

Chapter 12

Measurement

• “rules for assigning numbers to objects in such a way as to represent quantities of attributes”

• Marketers are interested in measuring many attributes that most people rarely think in terms of numbers.

• There are four types of scales used to measure attributes of objects:

Scales of Measurement

Ratio

Interval

Ordinal

Nominal

HIG

HE

R

Higher levels of measurement have all the properties of lower levels of measurement.

NOMINAL SCALE: measurement in which numbers are assigned to objects solely for the purpose of

identification Basic Measures of Comparisons Examples Average

Identity male-female mode (the most frequently occurring category)

user-nonuseroccupations

Which of the following soft drinks do you like? Check all that apply.

Coca-Cola Mountain Dew Seven Up Dr. Pepper PepsiSprite

Ordinal Scale: measurement in which numbers are assigned to data on the basis of some order (more than,

greater than) of the objects

Basic Measures of Comparisons Examples Average

Order brand preference median social class hardness of minerals lumber quality grades

Rank the following soft drinks from 1 (least liked) to 6 (most liked):

___Coca-Cola ___Mountain Dew ___Seven Up

___Dr. Pepper ___Pepsi ___Sprite

Interval Scale: measurement in which the assigned numbers allow the comparison of the size of the

differences among and between numbers


Comparison temperature meanof intervals grade point avg.

brand attitude company image

What is your overall opinion about each of these brands?

unfavorable favorableCoca-Cola 1 2 3 4 5 6 7Dr. Pepper 1 2 3 4 5 6 7Pepsi 1 2 3 4 5 6 7Sprite 1 2 3 4 5 6 7

Ratio Scale: measurement that has a natural, or absolute, zero and therefore allows the comparison of absolute magnitudes of the

numbers. Zero means that none of the property being measured exists.


Comparison units sold geometricof absolute # of purchases mean magnitudes age

income

Divide 100 points among these soft drinks according to your likelihood of purchasing each within the next week:

___Coca-Cola ___Mountain Dew ___Seven Up

___Dr. Pepper ___Pepsi ___Sprite

Methods for Assessing Attitude

• Three General Types of Self-Report Attitude Scales (A method of assessing attitudes in which individuals are asked directly for their beliefs about or feelings toward an object or class of objects)

1. Itemized-Ratings Scales

2. Graphic-Ratings Scales

3. Comparative-Ratings Scales

Measuring Attitudes and Other Unobservable Concepts

1. Itemized-Ratings Scales Summated Ratings (Likert) Scale

• A self-report technique for attitude measurement in which the subjects are asked to indicate their degree of agreement or disagreement with each of a number of statements.

• An individual’s attitude score is the total obtained by summing (or averaging) over the items in the scale.

Example of Likert (Summated-Ratings) Scale

StronglyDisagree

Disagree Agree

NeitherAgree norDisagree

StronglyAgree

The celebrity endorser is trustworthy.

The celebrity endorser is unattractive.

The celebrity endorser is an expert on the product.

The celebrity endorser is not knowledgeable about the product.

Example of Itemized Rating Scale

Please evaluate each of the following attributes of compact disc players according to how important the attribute is to you personally by checking the appropriate box.

1. Sound Quality

2. Physical Size

3. Brand Name

4. Durability

Not Somewhat Fairly Extremely Important Important Important Important

Itemized-Ratings Scales Semantic-Differential Scale

• A self-report technique for attitude measurement in which respondents are asked to check which cell between a set of bipolar adjectives or phrases best describes their feelings toward the object.

Example of Semantic-Differential Scale

Le Bron – Nike

Tiger Woods – Nike

KnowledgeableNotKnowledgeable: : : : : :

Not ExpertExpert : : : : : :

Attractive Unattractive: : : : : :

NotTrustworthyTrustworthy

: : : : : :

Semantic Differential Scale

KnowledgeableNotKnowledgeable

Not ExpertExpert

Attractive Unattractive

NotTrustworthyTrustworthy

x

x

x

x

o

o

o

o

LeBron

Tiger Woods

2. Graphic rating scales

Raters indicate their rating by placing a check at the appropriate point on a line that runs from one extreme of the attribute to the other

The score is assessed by measuring the length of the line from one end to the marked position

Example of Graphic Rating Scale

Please evaluate each of the following attributes of compact disc players according to how important the attribute is to you personally by placing an “X” at the position on the horizontal line that most accurately reflects your feelings.

Attribute Not ImportantImportant

1. Sound Quality

2. Physical Size

3. Brand Name

4. Durability

Respondents are asked to judge each attribute with direct reference to the other attributes being evaluated

Comparative Rating Scale

Comparative Rating Scale

Please divide 100 points between the following attributes of compact disc players according to the relative importance of each attribute to you.

Sound Quality

Physical Size

Brand Name

Durability100 points

Interpreting Rating Scales:Raw Scores vs. Norms

• A service provider received an average score of 5.13 on a 1-7 service quality scale, where 1 = “much less than I expected” and 7 = “much more than I expected.”

Is this score good or bad?


• Would your answer change if you knew that 75% of similar service providers posted higher scores than 5.13?

• It is very difficult to interpret a rating scale score using only the score itself and the scale on which it was obtained to provide meaning. A comparative standard, or norm, is needed.


Population-based norms give meaning to scores by comparing them to scores

obtained by similar entities

Time-based norms track scores for an entity over time and they are useful for

tracking progress and identifying problem area

Other Considerations in Designing Scales

• Reverse ScalingResponse set bias when respondents begin to answer all the

questions in a similar way due to boredom or lack of attention

• Number of Items in a Scale If an overall summary judgment is needed: global measureIf more information about how various aspects of the phenomenon

are viewed by respondents: composite measuresMore items are better than fewer items

• Number of Scale PositionsScales with 5-9 positions are used routinely in marketing research

• Including a “Don’t Know” CategoryUse when high percentage of respondents are likely not to have

encountered or thought about the object or issue in the study

• Determining Which Type of Scale to UseLet common sense guide your choice. Some cultures may not be

familiar with these scales.

Establishing the Validity and Reliability of Measures

SYSTEMATIC ERRORError in measurement that is also known as

constant error since it affects the measurement in a constant way.

RANDOM ERRORError in measurement due to temporary aspects

of the person or measurement situation that affects the measurement in irregular ways.

RANDOM SYSTEMATIC ERROR ERROR

RELIABILITYAbility of a measure to obtain similar scores for the same object, trait, or construct across time, across

different evaluators, or across the items forming the measure.

VALIDITYThe extent to which differences in scores on a measuring

instrument reflect true differences among individuals, groups, or situations in the characteristic that it seeks to

measure or true differences in the same individual, group, or situation from one occasion to another, rather

than systematic or random errors.

Unreliable Reliable Reliable Not Valid Not Valid Valid

A measure can be reliable but not valid.

A valid measure must be reliable.

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Collecting Data by Communication Chapter 12. Measurement “rules for assigning numbers to objects in such a way as to represent quantities of attributes”