Measurement and Scaling Slide 1© Associate Professor Dr. Jamil Bojei, 2007

Measurement and Scaling

Slide 1© Associate Professor Dr. Jamil Bojei, 2007



MEASUREMENT

• Measurement means assigning numbers or other symbols to characteristics of objects being measured, according to predetermined rules.



SCALING



SCALING

• Scaling may be considered a part of measurement. Scales place the object being measured along a continuum.



Primary Scales of Measurement

Primary Scales

Nominal Scale

Ordinal Scale

RatioScale

IntervalScale



PRIMARY SCALES OF MEASUREMENT

• Nominal scales A nominal scales uses numbers as labels or tags

for identifying and classifying objects.




• Ordinal scales – is a ranking scale, in an ordinal scale, numbers are assigned to objects which allows researchers to determine whether an object has more or less of a characteristics than some other object.




• Interval scale In an interval scale, numerically equal distances

on the scale represent equal values in the characteristics being measured.




• Ratio scale A ratio scales possess all the properties of the

nominal, ordinal, and interval scales. In addition, an absolute zero point is specified; that is, the origin of the scale is fixed.



Primary Scales Measurement

Scale

Nominal Numbers Assigned 17 21 13 Finish to Runners

Ordinal Rank Order Third Second First Finish of winners Place Place Place

Interval Performance Rating on a 74 90 97 0 to 100 scale

Ratio Time to Finish, in Seconds 16.1 14.0 13.2



Primary scales of measurementScale Basic characteristics Common

examplesMarketing examples

Permissible statistics

Nominal Numbers identify and classify objects.

Identification Card, numbering of football players.

Brands numbers, store types, sex classification

Percentages, mode

Ordinal Numbers indicate the relative positions of the objects but not the magnitude of differences between them.

Quality rankings, ranking of teams in a tournament

Preference ranking, market position, social class

Percentile, median

Interval Differences between objects can be compared; zero point is arbitrary

Temperature (Fahrenheit, Celsius)

Attitudes, opinions, index numbers

Range, mean, standard deviation

Ratio Zero point is fixed; rations of scale values can be computed

Length, weight Age, income, costs, sales, market shares.

Geometric mean (All)

Source: Maholtra, N.K. (2004) Marketing Research: An Applied Orientation. Upper-Saddle River, New Jersey, USA: Pearson Education Inc.



A Classification of Scaling Techniques

ScalingTechniques

ComparativeScales

PairedComparison

ConstantSum

RankOrder

NoncomparativeScales

ItemizedRating Scales

Continuous Rating Scales

Likert

Semantic Differential

Stapel



CLASSIFICATION OF SCALING TECHNIQUES

• Comparative scales – one of two types of scaling techniques in which there is direct comparison of stimulus objects with one another.




• Comparative Paired comparison scaling – a respondent is

presented with a pair of alternatives and asked to select one according to some criterion



Paired Comparison Scaling

InstructionsWe are going to present you with ten pairs of shampoo brands. For each pair, pleaseindicate which one of the two brands of shampoo in the pair you would prefer forpersonal use.Recording Form

A A 1 in a particular box means that the brand in that column was preferred over the brand in the corresponding row. A 0 means that the row brand was preferred over the column brand.B The number of times a brand was preferred is obtained by summing the 1s in each column.

Jhirmack

Finesse

Vidal SassoonHead & Shoulders

Pert

Number of timespreferred

Jhirmack Finesse Vidal Sassoon Head & Shoulders Pert

0

1

0

1

23B 0 4

00

0

0

1

1

1

1

1A

1

0

1

0

0

0

0

1




• Comparative Rank order scaling – the respondents are

presented with several alternatives simultaneously and are asked to rank them according to some criterion.



Rank Order Scaling

InstructionsRank the various brands of toothpaste in order of preference. Begin by picking out the one brand that you like most and assign it a number 1. Then find the second most preferred-brand and assign it a number 2. Continue this procedure until you have ranked all the brands of toothpaste in order of preference. The least preferred brand should be assigned aa rank of 10.

No two brands should receive the same rank number.

The criterion of preference is entirely up to you. There is no right or wrong answer. Justtry to be consistent.

Brand Rank Order 1. Crest 2. Colgate 3. Aim 4. Mentadent 5. Macleans 6. Ultra Brite 7. Close Up 8. Pepsodent 9. Plus White10. Stripe




• Comparative Constant sum scaling – respondent allocate a

constant sum o units, such a points, dollars, or chips among a set of alternatives according to some specified criterion.



Figure 9.8 Constant Sum Scaling

InstructionsBelow are eight attributes of bathing soaps. Please allocate 100 points among the attributes so that your allocation reflects the relative importance you attach to each attribute. The more points an attribute receives, the more important the attribute is. If an attribute is not at all important, assign it zero points. If an attribute is twice as important as someother attribute, it should receive twice as many points.

Form

AVERAGE RESPONSES OF THREE SEGMENTS Attribute Segment I Segment II Segment III 1. Mildness 8 2 4 2. Lather 2 4 17 3. Shrinkage 3 9 7 4. Price 53 17 9 5. Fragrance 9 0 19 6. Packaging 7 5 9 7. Moisturizing 5 3 20 8. Cleaning Power 13 60 15 Sum 100 100 100



Relative Advantages of Comparative Scales

• Small differences between stimulus objects can be detected.

• Same known reference points for all respondents.

• Easily understood and can be applied.

• Involve fewer theoretical assumptions.

• Tend to reduce halo or carryover effects from one judgment to another.



Relative Disadvantages of Comparative Scales

• Ordinal nature of the data

• Inability to generalize beyond the stimulus objects scaled.




• Non-comparative scales One of two types of scaling techniques in

which each stimulus objects is scaled independently of the other.



A Classification of Noncomparative Rating Scales

Noncomparative Rating Scales

ContinuousRating Scales

ItemizedRating Scales

SemanticDifferential

Stapel Likert



SCALING TECHNIQUES

• Non-comparative Continuous scaling – allows the respondents to

place a mark at any point along a line running between two extreme points rather than selecting from among a set o predetermined response categories.



Continuous Rating Scale

Respondents rate the objects by placing a mark at the appropriate position

on a line that runs from one extreme of the criterion variable to the other.

The form of the continuous scale may vary considerably.

How would you rate Sears as a department store?

Version 1

Probably the worst - - - - - - -I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Probably the best

Version 2

Probably the worst - - - - - - -I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - Probably the best

0 10 20 30 40 50 60 70 80 90100

Version 3

Very bad Neither good Very good

nor bad

Probably the worst - - - - - - -I - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - -Probably the best

0 10 20 30 40 50 60 70 80 90100



TABLE 10.1 Basic Noncomparative Scales Scale Basic Characteristics Examples Advantages Disadvantages Continuous Place a mark on a Reaction to TV Easy to construct Scoring can be Rating Scale continuous line commercials cumbersome unless computerized Itemized Rating Scales Likert Scale Degree of agreement on a Measurement of Easy to construct, More time 1 (strongly disagree) to attitudes administer, and consuming 5 (strongly agree) scale understand Semantic Seven-point scale with Brand, product, and Versatile Difficult to construct Differential bipolar labels company images appropriate bipolar adjectives Stapel Scale Unipolar ten-point scale, Measurement of Easy to construct Confusing and -5 to +5, without a neutral attitudes and Administered over difficult to point (zero) images telephone apply




• Non-comparative (itemised rating scales Likert – a measurement scale with five

response categories ranging from “strongly agree” to “strongly disagree”, which requires the respondent to indicate a degree of agreement or disagreement with each of series of statements related to the stimulus object.



Likert ScaleThe Likert scale requires the respondents to indicate a degree of agreement ordisagreement with each of a series of statements about the stimulus objects.

Strongly Disagree Neither Agree Strongly disagree agree nor agree

disagree 1. Sears sells high quality merchandise. 1 2X 3 4 5 2. Sears has poor in-store service. 1 2X 3 4 5 3. I like to shop at Sears. 1 2 3X 4 5

• The analysis can be conducted on an item-by-item basis (profile analysis), or a total (summated) score can be calculated.

• When arriving at a total score, the categories assigned to the negative statements by the respondents should be scored by reversing the scale.




• Semantic differential A seven-point rating scale with end points

associated with bipolar labels that have semantic meaning.



Semantic Differential ScaleThe semantic differential is a seven-point rating scale with end

points associated with bipolar labels that have semantic meaning.

SEARS IS:

Powerful --:--:--:--:-X-:--:--: Weak

Unreliable --:--:--:--:--:-X-:--: Reliable

Modern --:--:--:--:--:--:-X-: Old-fashioned

• The negative adjective or phrase sometimes appears at the left side of the scale and sometimes at the right.

• This controls the tendency of some respondents, particularly those with very positive or very negative attitudes, to mark the right- or left-hand sides without reading the labels.

• Individual items on a semantic differential scale may be scored on either a -3 to +3 or a 1 to 7 scale.




• Stapel scale A scale for measuring attitudes that consists of

a single adjective in the middle of an even-numbered ranged of values



Stapel ScaleThe Stapel scale is a unipolar rating scale with ten categoriesnumbered from -5 to +5, without a neutral point (zero). This scaleis usually presented vertically.

SEARS

+5 +5+4 +4+3 +3+2 +2X+1 +1

HIGH QUALITY POOR SERVICE-1 -1-2 -2-3 -3-4X -4-5 -5

The data obtained by using a Stapel scale can be analyzed in thesame way as semantic differential data.



Surfing the Internet is

____ Extremely Good

____ Very Good

____ Good

____ Bad

____ Very Bad

____ Extremely Bad

Surfing the Internet is

____ Extremely Good

____ Very Good

____ Good

____ Somewhat Good

____ Bad

____ Very Bad

Balanced Scale Unbalanced Scale

Figure 10.4 Balanced and Unbalanced Scales



Thermometer ScaleInstructions: Please indicate how much you like McDonald’s hamburgers by coloring in the thermometer. Start at the bottom and color up to the temperature level that best indicates how strong your preference is. Form:

Smiling Face Scale Instructions: Please point to the face that shows how much you like the Barbie Doll. If you do not like the Barbie Doll at all, you would point to Face 1. If you liked it very much, you would point to Face 5.

Form: 1 2 3 4 5

Like very much

Dislike very much

100 75 50 25 0

Some Unique Rating Scale Configurations



Figure 10.7 Scale Evaluation

Scale Evaluation

ReliabilityValidity

Test-RetestInternal

ConsistencyAlternative

Forms Construct

Criterion

Content

Convergent Validity

Discriminant Validity

NomologicalValidity



Relationship Between Reliability and Validity

• If a measure is perfectly valid, it is also perfectly reliable. In this case there is no random or systematic error.

• If a measure is unreliable, it cannot be perfectly valid, since at a minimum random error is present. Thus, unreliability implies invalidity.

• If a measure is perfectly reliable, it may or may not be perfectly valid, because systematic error may still be present.

• Reliability is a necessary, but not sufficient, condition for validity.

Documents

Measurement and Scaling Slide 1© Associate Professor Dr. Jamil Bojei, 2007