3 measurement scales

8/22/2019 3 Measurement Scales

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Measurement and Scaling


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Concept of Attitude

Mental state of an individual which makeshim to act or respond for or against,

situations etc. with which his/her vestedfeelings of interest, liking, desire and so on,are directly or indirectly linked or associated.


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Scaling involves creating a continuum upon

which measured objects are located.

Consider an attitude scale from 1 to 100.

Each respondent is assigned a number from 1 to 100,

with 1 = Extremely Unfavorable, and 100 =Extremely Favorable.

Measurement is the actual assignment of a number

from 1 to 100 to each respondent.

Scaling is the process of placing the respondents ona continuum with respect to their attitude toward anobject.


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Types of Scales

Attitude measurement is qualitative andabstract in nature. The four widely acceptedlevels of measurement called measurement

scales are:

Nominal Scale

Ordinal Scale

Interval Scale

Ratio Scale


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Nominal Scale

The numbers serve only as labels or tags for identifying andclassifying objects.

When used for identification, there is a strict one-to-onecorrespondence between the numbers and the objects.

The numbers do not reflect the amount of the characteristicpossessed by the objects.

It is a system of classification and does not place the entity alonga continuum

The only permissible operation on the numbers in a nominalscale is counting.

Only a limited number of statistics, all of which are based onfrequency counts, are permissible, e.g., percentages, and mode.


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Ordinal Scale

A ranking scale in which numbers are assigned to objects to indicatethe relative extent to which the objects possess some characteristic.

Can determine whether an object has more or less of a characteristicthan some other object, but not how much more or less.

Any series of numbers can be assigned that preserves the orderedrelationships between the objects.

From such a table the researcher knows the order of preference butnothing about how much more one brand is preferred to another, that isthere is no information about the interval between any two brands

In addition to the counting operation allowable for nominal scale data,ordinal scales permit the use of statistics based on centiles, e.g.,percentile, quartile, median.

Lowest level of ordered scale. Do not have an absolute value.


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Interval Scale

Numerically equal distances on the scale represent equal values in thecharacteristic being measured. It is adjusted in terms of some rule thathas been established as a basis for making the units equal.

It has an arbitrary zero but not an absolute one.

It permits comparison of the differences between objects.

The interval or cardinal scale has equal units of measurement, thusmaking it possible to interpret not only the order of scale scores butalso the distance between them

The location of the zero point is not fixed. Both the zero point and theunits of measurement are arbitrary.

It is not meaningful to take ratios of scale values.

Statistical techniques that may be used include all of those that can beapplied to nominal and ordinal data, and in addition the arithmeticmean, standard deviation, and other statistics commonly used inmarketing research.


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Ratio Scale

Possesses all the properties of the nominal, ordinal, and intervalscales.

It has an absolute zero point.

It is meaningful to compute ratios of scale values.

GM and HM are used to measure central tendency. andcoefficient of variation can be calculated.

All statistical techniques can be applied to ratio data


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Primary Scales of Measurement

Scale BasicCharacteristics

CommonExamples

MarketingExamples

Nominal Numbers identify

& classify objects

Social Security

nos., numbering

of football players

Brand nos., store

types

Percentages,

mode

Chi-square,

binomial test

Ordinal Nos. indicate the

relative positionsof objects but not

the magnitude of

differences

between them

Quality rankings,

rankings of teamsin a tournament

Preference

rankings, marketposition, social

class

Percentile,

median

Rank-order

correlation,Friedman

ANOVA

Ratio Zero point is fixed,

ratios of scale

values can be

compared

Length, weight Age, sales,

income, costs

Geometric

mean, harmonic

mean

Coefficient of

variation

Permissible StatisticsDescriptive Inferential

Interval Differences

between objects

Temperature

(Fahrenheit)

Attitudes,

opinions, index

Range, mean,

standard

Product-

moment


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ScaleNominal Numbers

Assigned

to Runners

Ordinal Rank Order

of Winners

Interval PerformanceRating on a0 to 10 Scale

Ratio Time to Finishin Seconds

Thirdplace

Secondplace

Firstplace

Finish

Finish

8.2 9.1 9.6

15.2 14.1 13.4


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Illustration of Primary Scales of Measurement

Nominal Ordinal Ratio

Scale Scale ScalePreference $ spent last

No. Store Rankings 3 months

1. Lord & Taylor2. Macys

3. Kmart

4. Richs

5. J.C. Penney

6. Neiman Marcus7. Target

8. Saks Fifth Avenue

9. Sears

10.Wal-Mart

IntervalScalePreferenceRatings

1-7 11-177 79 5 15 0

2 25 7 17 200

8 82 4 14 0

3 30 6 16 100

1 10 7 17 250

5 53 5 15 35

9 95 4 14 0

6 61 5 15 100

4 45 6 16 0

10 115 2 12 10


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Test of sound measurement

Sound measurement must meet the test of validity,reliability and practicality.

Validity refers to the extent to which a test measureswhat we actually wish to measure

Reliability has to do with accuracy and precision of ameasurement procedure.

Practicality is concerned with factors like economy,convenience and interpretability.


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Comparative scales involve the direct comparisonof stimulus objects. Comparative scale data mustbe interpreted in relative terms and have only ordinalor rank order properties.

In noncomparative scales, each object is scaledindependently of the others in the stimulus set. The

resulting data are generally assumed to be intervalor ratio scaled


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Paired Comparison Scaling

A respondent is presented with two objects and asked to selectone according to some criterion.

The data obtained are ordinal in nature.

Paired comparison scaling is the most widely used comparativescaling technique.

With n brands, [n(n - 1) /2] paired comparisons are required.

Under the assumption of transitivity, it is possible to convert

paired comparison data to a rank order.


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The most common method of taste testing is paired comparison.The consumer is asked to sample two different products and

select the one with the most appealing taste. The test is done inprivate and a minimum of 1,000 responses is considered anadequate sample.

A blind taste test for a soft drink, where imagery, self-perception and brand reputation are very important factors inthe consumers purchasing decision, may not be a goodindicator of performance in the marketplace.

The introduction of New Coke illustrates this point. New Cokewas heavily favored in blind paired comparison taste tests, butits introduction was less than successful, because image plays amajor role in the purchase of Coke.


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Rank Order Scaling

Respondents are presented with several objectssimultaneously and asked to order or rank themaccording to some criterion.

It is possible that the respondent may dislike thebrand ranked 1 in an absolute sense.

Furthermore, rank order scaling also results in

ordinal data. Only (n - 1) scaling decisions need be made in rank

order scaling.


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Example

Instructions: Rank the various brands of toothpaste in order ofpreference. Begin by picking out the one brand that you likemost and assign it a number 1. Then find the second mostpreferred brand and assign it a number 2. Continue this

procedure until you have ranked all the brands of toothpaste inorder of preference. The least preferred brand should beassigned a rank of 10.

No two brands should receive the same rank number.

The criterion of preference is entirely up to you. There is no rightor wrong answer. Just try to be consistent.


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Constant Sum Scaling

Respondents allocate a constant sum of units, such as 100 points to

attributes of a product to reflect their importance.

If an attribute is unimportant, the respondent assigns it zero points.

If an attribute is twice as important as some other attribute, it receivestwice as many points.

The sum of all the points is 100. Hence, the name of the scale.

Respondents allocate a constant sum of units, such as 100 points toattributes of a product to reflect their importance.

If an attribute is unimportant, the respondent assigns it zero points.

If an attribute is twice as important as some other attribute, it receivestwice as many points.

The sum of all the points is 100. Hence, the name of the scale.


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Example

Instructions

On the next slide, there are eight attributes of bathing soaps.Please allocate 100 points among the attributes so that your

allocation reflects the relative importance you attach to eachattribute.

The more points an attribute receives, the more important theattribute is. If an attribute is not at all important, assign it zero

points. If an attribute is twice as important as some otherattribute, it should receive twice as many points.


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Average Responses of Three Segments of soaps

Attribute Segment I Segment II Segment III

1. Mildness - - -

2. Lather - - -

3. Shrinkage - - -4. Price - - -

5. Fragrance - - -

6. Packaging - - -

7. Moisturizing - - -

8. Cleaning Power - - -


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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 toanother.


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Relative Disadvantages of Comparative Scales

Ordinal nature of the data

Inability to generalize beyond the stimulus objects scaled.


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Sample question for paired comparative scaling

A combination of exploratory research and shrewd observation

suggested that the following factors played a role in the shaping ofthe attitudes of those farmers who feel negatively towards a newagricultural design:

Does not fold Does not work for inter-cropping Far too expensive New technology too risky Too difficult to carry.

Suppose the organisation responsible wants to know which factors isforemost in the farmer's mind. It may well be the case that if thosefactors that are most important to the farmer than the others, beingof a relatively minor nature, will cease to prevent widespreadadoption.


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The process of rank ordering the objections from most to leastimportant is best approached through the questioning techniqueknown as 'paired comparison'. Each of the objections is paired bythe researcher so that with 5 factors, as in this example, there are10 pairs-

In 'paired comparisons' every factor has to be paired with every

other factor in turn. However, only one pair is ever put to the farmerat any one time.

The question might be put as follows:

Which of the following was the more important in making you decide

not to buy the plough?


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Below labels have been given to the factors so that the worked examplewill be easier to understand.

A =Does not ridge

B =Far too expensiveC =New technology too riskyD =Does not work for inter-croppingE =Too difficult to carry.

The data is then arranged into a matrix. Assume that 200 farmers have

been interviewed and their responses are arranged in the grid below.Further assume that the matrix is so arranged that we read from top toside.


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Non-comparative Scaling Techniques

Respondents evaluate only one object at atime, and for this reason non-comparativescales are often referred to as monadic

scales.

Non-comparative techniques consist ofcontinuous and itemized rating scales


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Continuous Rating Scale

Respondents rate the objects by placing a mark at the appropriate position on a linethat 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 90 100

Version 3Very bad Neither good Very good

nor bad

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

0 10 20 30 40 50 60 70 80 90 100


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Itemized Rating Scales

The respondents are provided with a scale that has a number orbrief description associated with each category.

The categories are ordered in terms of scale position, and therespondents are required to select the specified category thatbest describes the object being rated.

The commonly used itemized rating scales are the

Likert

Semantic differential

Stapel scales.


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Likert Scale

The Likert scale requires the respondents to indicate a degree of agreement or disagreement

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 therespondents should be scored by reversing the scale.


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Semantic Differential Scale

The semantic differentialis a seven-point rating scale with end pointsassociated 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 ofthe 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-handsides without reading the labels.

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


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1) Rugged :---:---:---:---:---:---:---: Delicate

2) Excitable :---:---:---:---:---:---:---: Calm

3) Uncomfortable :---:---:---:---:---:---:---: Comfortable

4) Dominating :---:---:---:---:---:---:---: Submissive

5) Thrifty :---:---:---:---:---:---:---: Indulgent

6) Pleasant :---:---:---:---:---:---:---: Unpleasant

7) Contemporary :---:---:---:---:---:---:---: Obsolete

8) Organized :---:---:---:---:---:---:---: Unorganized

9) Rational :---:---:---:---:---:---:---: Emotional


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Stapel ScaleThe Stapel scale is a unipolar rating scale with ten categories numbered from -5 to

+5, without a neutral point (zero). This scale is 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 the same way as

semantic differential data.


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A Classification of Scaling Techniques

LikertSemanticDifferential Stapel

Scaling Techniques

Non comparative

Scales

Comparative

Scales

Paired

Comparison

Rank

Order

Constant

Sum

Continuous

Rating Scales

Itemized

Rating Scales


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3 measurement scales

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