Marketing Research Module 3 Non Comparitive Scaling

Ch apter Ni ne Measurement and Scaling: Noncomparative Scaling Techniques

© 2007 Prentice Hall

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Ch apter O utl ine 1) Overview 2) Noncomparative Scaling Techniques 3) Continuous Rating Scale 4) Itemized Rating Scale i.

Likert Scale

ii.

Semantic Differential Scale

iii. Stapel Scale © 2007 Prentice Hall

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Cha pter Ou tl ine 5) Noncomparative Itemized Rating Scale Decisions i.

Number of Scale Categories

ii. Balanced Vs. Unbalanced Scales iii. Odd or Even Number of Categories iv. Forced Vs. Non-forced Scales v. Nature and Degree of Verbal Description vi. Physical Form or Configuration 6) Multi-item Scales © 2007 Prentice Hall

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Cha pter Ou tl ine 7) Scale Evaluation i.

Measurement Accuracy

ii.

Reliability

iii. Validity iv. Relationship between Reliability and Validity v.

Generalizability

8) Choosing a Scaling Technique

Reliable?

Valid?

Generalizable?

9) Mathematically Derived Scales

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Cha pter Ou tl ine 10) International Marketing Research 11) Ethics in Marketing Research 12) Summary

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Nonc ompa ra ti ve S cali ng Te ch ni qu es 

Respondents evaluate only one object at a time, and for this reason non-comparative scales are often referred to as monadic scales.



Non-comparative techniques consist of continuous and itemized rating scales.

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Co nti nuous Rati ng S ca le 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 90 100 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 90 100 © 2007 Prentice Hall

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RATE: R api d A na lysi s a nd Test ing En vir on me nt A rel ativ el y new re sea rch too l, the perc ept ion analy zer, pr ovid es con tin uou s mea sure me nt of “gu t rea ct ion .” A gr oup of up to 400 re spon de nts is pre sen te d wi th TV or ra dio spot s or adve rt is ing copy . The measurin g de vic e con sists of a dia l that con ta in s a 100-poin t ra nge . Ea ch pa rt ic ipa nt is giv en a dia l and instru cte d to con tin uously re cord his or her re act ion to the mate ria l be in g te ste d . As th e re spon den ts tu rn th e di als , the in form ation is fed to a com pu ter , wh ich tabu la tes secon d-by -sec ond re spon se pr ofile s. As the res ult s are re corde d by the comp uter, they are super im pos ed on a vid eo scr een , enabli ng the res earch er to vie w th e re spon de nts' score s im med ia tel y. The res pon ses are also stored in a per ma nent da ta file for use in furt her analy sis. The re spon se score s ca n be brok en dow n by ca teg orie s, such as age, in com e, sex , or produ ct usage. © 2007 Prentice Hall

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Itemi ze d Rati ng Sc ales 

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



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



The commonly used itemized rating scales are the Likert, semantic differential, and Stapel scales.

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Li kert S ca le The Li ke rt sca le requires the respondents to indicate a degree of agreement or disagreement with each of a series of statements about the stimulus objects.

1. Sears sells high quality merchandise.

Strongly disagree

Disagree

Neither Agree agree nor disagree

Strongly agree

1

2X

3

4

5

1

2X

3

4

2

3X

4

5

2. Sears has poor in-store service. 3. I like to shop at Sears.

1

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.

© 2007 Prentice Hall

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Se man ti c Di ffere nti al Sc al e The seman tic diffe re nt ial 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.

© 2007 Prentice Hall

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A Seman ti c D if ferenti al Sca le f or Me asuri ng Self - Conc ep ts, Person Conc ept s, and Product Conce pts 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

10) Youthful © 2007 11) Prentice Hall Formal

:---:---:---:---:---:---:---: Mature :---:---:---:---:---:---:---: Informal

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St apel Sc al e The St ap el 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 +4 +3 +2 +1 HIGH QUALITY -1 -2 -3 -4X -5

+5 +4 +3 +2X +1 POOR SERVICE -1 -2 -3 -4 -5

The data obtained by using a Stapel scale can be analyzed in the same way as semantic differential data. © 2007 Prentice Hall

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Basic Nonc omp ara ti ve S ca les Table 9.1 Scal e

Bas ic Charac ter is tics

Ex ampl es

Ad vantages

Dis adv antages

Continuous Rating Scale

Place a mark on a continuous line

Reaction to TV commercials

Easy to construct

Scoring can be cumbersome unless computerized

Itemized Rating Scales Likert Scale

Degrees of agreement on a 1 (strongly disagree) to 5 (strongly agree) scale

Measurement of attitudes

Easy to construct, administer, and understand

More time-consuming

Semantic Differential

Seven - point scale with bipolar labels

Brand, product, and company images

Versatile

Controversy as to whether the data are interval

Stapel Scale

Unipolar ten - point scale, - 5 to +5, witho ut a neutral point (zero)

Measurement of attitudes and images

Easy to construct, administer over telephone

Confusing and difficult to apply

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Summary of Itemized Scale Decisions Table 9.2 1) N um ber of categ ories number,

2) Bal anced vs. unb ala nc ed

Although there is no single, optimal traditional guidelines suggest that there should be between five and nine categories In general, the scale should be balanced to obtain objective data

3) O dd/even no. of cate gor ie s If a neutral or indifferent scale response is possible for at least some respondents, an odd number of categories should be used 4) Fo rced vs. non- forced

In situations where the respondents are expected to have no opinion, the accuracy of the data may be improved by a non-forced scale

5) Ve rb al des crip tio n

An argument can be made for labeling all or many scale categories. The category descriptions should be located as close to the response categories as possible

6) Physi cal fo rm

A number of options should be tried and the best selected

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Bal anced a nd Unbalan ce d Sca les Fig. 9.1

Jovan Musk for Men is: Extremely good Very good Good Bad Very bad Extremely bad

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Jovan Musk for Men is: Extremely good Very good Good Somewhat good Bad Very bad

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Rati ng S ca le C onfig ura ti ons Fig. 9.2

Cheer detergent is: 1) Very harsh

---

2) Very harsh

1

--2

3) . Very harsh . . . Neither harsh nor gentle . . . Very gentle 4) ____ Very harsh

-3

____ Harsh

-2

---

---

---

---

---

Very gentle

3

4

5

6

7

Very gentle

Cheer

____ ____ Somewhat Neither harsh Harsh nor gentle

-1

0

____ Somewhat gentle

+1

____ Gentle

+2

____ Very gentle

+3

5) Very harsh © 2007 Prentice Hall

Neither harsh nor gentle

Very gentle 9-17

Som e Unique Ra ti ng Scale Conf igura tio ns Fig. 9.3 Thermometer Scale Instructions: 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: Like very 100 75 much 50 25 0

Dislike very much

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: © 2007 Prentice Hall

1

2

3

4

5

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Some Co mm on ly U sed Scales in Ma rk eting Table 9.3 SCALE DESCRIPTORS

CONSTRUCT Attitude

Very Bad

Bad

Neither Bad Nor Good

Good

Very Good

Importance

Not all All Important

Not Important

Neutral

Important

Very Important

Satisfaction

Very Dissatisfied

Dissatisfied

Neither Dissat Nor Satisfied Satisfied

Very Satisfied

Purchase Intent

Definitely will Not Buy

Probably Will Not Buy

Might or Might Not Buy

Probably Will Buy

Definitely Will Buy

Purchase Freq

Never

Rarely

Sometimes

Often

Very Often

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De velo pm ent of a Mul ti-i tem S ca le Fig. 9.4 De vel op T he ory Ge nerat e Ini tial Poo l of It em s: T heory , Sec ond ary Dat a, a nd Qual it ative R esea rch Sel ect a Red uc ed Set of It em s Based on Quali tat ive Jud geme nt Collec t Dat a fr om a L arg e Pret est Sam ple St atist ica l A nalysis Dev elop Puri fi ed Scal e Col lec t More Dat a fro m a Diff erent Sam ple Eval uat e Scal e Rel iab il ity, Vali dity, and Generali zab ility Fi na l Scal e © 2007 Prentice Hall

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Sca le E va lua ti on Fig. 9.5 Scale Evaluation

Reliability

Test/ Retest

Alternative Forms

Validity

Internal Consistency

Content

Criterion

Convergent

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Generalizability

Construct

Discriminant Nomological

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Mea su remen t Ac cu ra cy The true sco re mo del provides a framework for understanding the accuracy of measurement. XO = XT + XS + XR where XO = the observed score or measurement XT = the true score of the characteristic XS = systematic error XR = random error © 2007 Prentice Hall

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Pot ent ial So urces of Er ror on Mea sure me nt Fig. 9.6 1) Other relatively stable characteristics of the individual that influence the test score, such as intelligence, social desirability, and education. 2) Short-term or transient personal factors, such as health, emotions, and fatigue. 3) Situational factors, such as the presence of other people, noise, and distractions. 4) Sampling of items included in the scale: addition, deletion, or changes in the scale items. 5) Lack of clarity of the scale, including the instructions or the items themselves. 6) Mechanical factors, such as poor printing, overcrowding items in the questionnaire, and poor design. 7) Administration of the scale, such as differences among interviewers. 8) Analysis factors, such as differences in scoring and statistical analysis. © 2007 Prentice Hall

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Rel iabi lity 

Rel iabi lit y can be defined as the extent to which measures are free from random error, XR . If XR = 0, the measure is perfectly reliable.



In test -ret est rel iab il it y, respondents are administered identical sets of scale items at two different times and the degree of similarity between the two measurements is determined.



In al te rna tiv e- forms r eli ab il ity , two equivalent forms of the scale are constructed and the same respondents are measured at two different times, with a different form being used each time.

© 2007 Prentice Hall

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Rel iabi lity 





In ter nal co nsi stency rel ia bi li ty determines the extent to which different parts of a summated scale are consistent in what they indicate about the characteristic being measured. In sp li t-ha lf r eli ab il ity , the items on the scale are divided into two halves and the resulting half scores are correlated. The co efficien t al pha, or Cronbach's alpha, is the average of all possible split-half coefficients resulting from different ways of splitting the scale items. This coefficient varies from 0 to 1, and a value of 0.6 or less generally indicates unsatisfactory internal consistency reliability.

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Va lidi ty 

The vali dity of a scale may be defined as the extent to which differences in observed scale scores reflect true differences among objects on the characteristic being measured, rather than systematic or random error. Perfect validity requires that there be no measurement error (XO = XT, XR = 0, XS = 0).

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Co nten t va li dit y is a subjective but systematic evaluation of how well the content of a scale represents the measurement task at hand.

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Cr it eri on va lid it y reflects whether a scale performs as expected in relation to other variables selected (criterion variables) as meaningful criteria.

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Va lidi ty 

Co nst ruct v al idi ty addresses the question of what construct or characteristic the scale is, in fact, measuring. Construct validity includes convergent, discriminant, and nomological validity.



Co nver gen t val idi ty is the extent to which the scale correlates positively with other measures of the same construct.



Discr iminan t va li dit y is the extent to which a measure does not correlate with other constructs from which it is supposed to differ.



Nomo logical val id ity is the extent to which the scale correlates in theoretically predicted ways with measures of different but related constructs.

© 2007 Prentice Hall

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Rel ati onsh ip Between and Va lidi ty

Reli abili ty



If a measure is perfectly valid, it is also perfectly reliable. In this case XO = XT , XR = 0, and XS = 0.



If a measure is unreliable, it cannot be perfectly valid, since at a minimum XO = XT + XR . Furthermore, systematic error may also be present, i.e., XS ≠0. 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 (XO = XT + XS ).



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

© 2007 Prentice Hall

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