Measurement scaling

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Measurement scaling

  1. 1. Measurement - ScalingMeasurement - ScalingThere are two main categories of attitudinal scales,There are two main categories of attitudinal scales,1.1. The rating scalesThe rating scales2.2. The ranking scalesThe ranking scalesRating scalesRating scales have several response categories and are used to elicithave several response categories and are used to elicitresponses with regard to the object, event, or person studied.responses with regard to the object, event, or person studied.Ranking scalesRanking scales make comparison between or among objects, events, ormake comparison between or among objects, events, orpersons and elicit the preferred choices and ranking them.persons and elicit the preferred choices and ranking them.
  2. 2. Rating ScalesRating ScalesTypes of rating scales,Types of rating scales,1.1. Dichotomous scaleDichotomous scale2.2. Category scaleCategory scale3.3. Likert scaleLikert scale4.4. Numerical scaleNumerical scale5.5. Semantic differential scaleSemantic differential scale6.6. Itemized rating scaleItemized rating scale7.7. Fixed or constant sum rating scaleFixed or constant sum rating scale8.8. Stapel scaleStapel scale9.9. Graphic rating scaleGraphic rating scale10.10. Consensus scaleConsensus scale
  3. 3. Rating ScalesRating Scales1.1. Dichotomous Scale :Dichotomous Scale :It is used to elicit a Yes or No answer. Note a nominal scale is used toIt is used to elicit a Yes or No answer. Note a nominal scale is used toelicit the response.elicit the response.Ex:Ex: Do you own a car?Do you own a car? YesYes NoNo2. Category Scale :2. Category Scale :Uses multiple items to elicit a single response as per the followingUses multiple items to elicit a single response as per the followingexample. This also uses the nominal scale.example. This also uses the nominal scale.Ex:Ex: Where in northern California do you reside?Where in northern California do you reside?- North BayNorth Bay- South BaySouth Bay- East BayEast Bay- PeninsulaPeninsula- otherother
  4. 4. Rating ScalesRating Scales3. Likert Scale:3. Likert Scale:It is designed to examine how strongly subjects agree or disagree withIt is designed to examine how strongly subjects agree or disagree withstatements on a 5-point scale with following anchorsstatements on a 5-point scale with following anchorsStronglyStrongly DisagreeDisagree Neither AgreeNeither Agree AgreeAgree StronglyStronglyAgreeAgree Nor DisagreeNor Disagree AgreeAgree11 22 33 44 55Ex:Ex: using the likert scale, state the extent to which you agree with eachusing the likert scale, state the extent to which you agree with eachof the following statements:of the following statements:My work is very interestingMy work is very interesting 11 22 33 44 55I am not engrossed in myI am not engrossed in mywork all daywork all day 11 22 33 44 55Life without my work willLife without my work willbe dullbe dull 11 22 33 44 55
  5. 5. Rating ScalesRating Scales4. Semantic Differential Scale:4. Semantic Differential Scale:Several bipolar attributes are identified at the extremes of the scale, andSeveral bipolar attributes are identified at the extremes of the scale, andrespondents are asked to indicate their attitudes, on what may be called arespondents are asked to indicate their attitudes, on what may be called asemantic space, toward a particular individual, object or event on each ofsemantic space, toward a particular individual, object or event on each ofthe attributes.the attributes.The bipolar adjectives used, for instance, would employ such terms as,The bipolar adjectives used, for instance, would employ such terms as,Good- Bad, Strong – Weak, Hot-Cold.Good- Bad, Strong – Weak, Hot-Cold.Ex:Ex: Responsive ------------------------ UnresponsiveResponsive ------------------------ UnresponsiveBeautiful --------------------------- UglyBeautiful --------------------------- UglyCourageous ------------------------ TimidCourageous ------------------------ Timid
  6. 6. Rating ScalesRating Scales5. Numerical Scale :5. Numerical Scale :It is similar to semantic differential scale, with the difference thatIt is similar to semantic differential scale, with the difference thatnumbers on a 5 point or 7 point scale are provided, with bipolarnumbers on a 5 point or 7 point scale are provided, with bipolaradjectives at both ends, as illustrated below. This is also an interval scale.adjectives at both ends, as illustrated below. This is also an interval scale.Ex:Ex: How pleased are you with your new real estate agent?How pleased are you with your new real estate agent?ExtremelyExtremely 77 66 55 44 33 22 1 Extremely1 ExtremelyPleasedPleased DispleasedDispleased
  7. 7. Rating ScalesRating Scales6. Itemized rating Scale:6. Itemized rating Scale:A 5 point or 7 point scale with anchors, as needed , is provided for eachA 5 point or 7 point scale with anchors, as needed , is provided for eachitem and the respondent states the appropriate number on the side ofitem and the respondent states the appropriate number on the side ofeach item, or circles the relevant number against each item, as pereach item, or circles the relevant number against each item, as perexample the follow,example the follow,Ex:Ex: Respond to each item using the scale below, and indicate yourRespond to each item using the scale below, and indicate yourresponse number on the line by each item.response number on the line by each item.11 22 33 44 55Very LikelyVery Likely UnlikelyUnlikely Neither Unlikely LikelyNeither Unlikely Likely Very LikelyVery LikelyNor LikelyNor Likely1.I will be changing my job within next 12 months1.I will be changing my job within next 12 months --------------------2. I will take on new assignments in the near future2. I will take on new assignments in the near future --------------------3. It is possible that I will be out of this organization3. It is possible that I will be out of this organization--------------------within the next 12 monthswithin the next 12 months
  8. 8. Rating ScalesRating Scales7. Fixed or Constant Sum scale :7. Fixed or Constant Sum scale :The respondents here are asked to distribute a given number of pointsThe respondents here are asked to distribute a given number of pointsacross various items as the example below. This is more in nature of anacross various items as the example below. This is more in nature of anordinal scale.ordinal scale.Ex:Ex: In choosing a toilet soap indicate the importance you attach to eachIn choosing a toilet soap indicate the importance you attach to eachof the following five aspects by allotting points for each to total 100 inof the following five aspects by allotting points for each to total 100 inall.all.FragranceFragrance ------ColorColor ------ShapeShape ------SizeSize ------Texture of latherTexture of lather ------Total PointsTotal Points 100100
  9. 9. Rating ScalesRating Scales8. Stapel Scale8. Stapel ScaleThis scale simultaneously measures both the direction and intensity of the attitudeThis scale simultaneously measures both the direction and intensity of the attitudetowards items under study. The characteristics of interest to the study is placed at thetowards items under study. The characteristics of interest to the study is placed at thecenter and a numerical scale ranging say, for +3 to – 3, on either side of the item iscenter and a numerical scale ranging say, for +3 to – 3, on either side of the item isillustrated below.illustrated below.Ex :Ex : Show how would you rate your supervisor’s abilities with respect to each of theShow how would you rate your supervisor’s abilities with respect to each of thecharacteristics mentioned below, by circling the appropriate number.characteristics mentioned below, by circling the appropriate number.+3+3 +3+3 +3+3+2+2 +2+2 +2+2+1+1 +1+1 +1+1Adopting modernAdopting modern ProductProduct InterpersonalInterpersonalTechnologyTechnology InnovationInnovation SkillsSkills-3-3 -3-3 -3-3-2-2 -2-2 -2-2-1-1 -1-1 -1-1
  10. 10. Rating ScalesRating Scales9. Graphic Rating Scale :9. Graphic Rating Scale :A graphical representation helps the respondents to indicate on this scaleA graphical representation helps the respondents to indicate on this scaletheir answers to a particular question by placing a mark at thetheir answers to a particular question by placing a mark at theappropriate point on the line, as in the following example.appropriate point on the line, as in the following example.Ex:Ex: On a scale of 1 to 10, how would you rate your supervisor,On a scale of 1 to 10, how would you rate your supervisor,--10--10 ExcellentExcellent------------------5--5 All RightAll Right-------------------- Very BadVery Bad
  11. 11. Rating ScalesRating Scales10. Consensus Scale :10. Consensus Scale :Scales are developed by consensus, where a panel of judges selectsScales are developed by consensus, where a panel of judges selectscertain items, which in its view measure the relevant concept. The itemscertain items, which in its view measure the relevant concept. The itemsare chosen particularly based on their pertinence or relevance to theare chosen particularly based on their pertinence or relevance to theconcept. Such a consensus scale is developed after the selected items areconcept. Such a consensus scale is developed after the selected items areexamined and tested for the validity and reliability.examined and tested for the validity and reliability.
  12. 12. Ranking ScalesRanking ScalesRanking scales are used to tap preferences between two or among moreRanking scales are used to tap preferences between two or among moreobjects or items (ordinal in nature).objects or items (ordinal in nature).Types :Types :1.1. Paired comparisonPaired comparison2.2. Forced choiceForced choice3.3. Comparative scaleComparative scale
  13. 13. Ranking ScalesRanking Scales1.1. Paired Comparison :Paired Comparison :Used when, among a small number of objects, respondents areUsed when, among a small number of objects, respondents areasked to choose between two objects at a time. This helps to assessasked to choose between two objects at a time. This helps to assesspreferences.preferences.The paired choices for n objects will be [(n)(n-1)/2].The paired choices for n objects will be [(n)(n-1)/2].
  14. 14. Ranking ScalesRanking Scales2. Forced Choice:2. Forced Choice:Enables respondents to rank objects relative to one another among theEnables respondents to rank objects relative to one another among thealternatives provided. This is easier for the respondent, particularly if thealternatives provided. This is easier for the respondent, particularly if thenumber of choices to be ranked is limited in number.number of choices to be ranked is limited in number.Ex:Ex: Rank the following magazines that you would like to subscribe to inRank the following magazines that you would like to subscribe to inthe order of preference, assigning 1 for the most preferred choice and 5the order of preference, assigning 1 for the most preferred choice and 5for the least preferred.for the least preferred.Business TodayBusiness TodayBusiness WorldBusiness WorldBusiness OutlookBusiness OutlookIndia todayIndia todayPC worldPC world
  15. 15. Ranking ScalesRanking Scales3. Comparative scale :3. Comparative scale :It provides a benchmark or a point of reference to assess attitudes towardIt provides a benchmark or a point of reference to assess attitudes towardcurrent object, event or situation under study.current object, event or situation under study.Ex :Ex : In a volatile financial environment, compared to stocks, how wise orIn a volatile financial environment, compared to stocks, how wise oruseful it is to invest in Mutual funds? Please circle the appropriateuseful it is to invest in Mutual funds? Please circle the appropriateanswer.answer.More usefulMore useful About the sameAbout the same Less usefulLess useful11 22 33 44 55
  16. 16. GOODNESS OF MEASURESGOODNESS OF MEASURESThe scales developed could often be imperfect, and errors are proneThe scales developed could often be imperfect, and errors are proneto occur in the measurement of attitudinal variables. The use ofto occur in the measurement of attitudinal variables. The use ofbetter instruments will ensure more accuracy in results, which inbetter instruments will ensure more accuracy in results, which inturn, will enhance the scientific quality of the research.turn, will enhance the scientific quality of the research.Hence in someway, we need to assess the “goodness” of theHence in someway, we need to assess the “goodness” of themeasures developed.measures developed.To ensure the measures developed are reasonably good, the followingTo ensure the measures developed are reasonably good, the followingmethods are used.methods are used.1.1. Item AnalysisItem Analysis2.2. ReliabilityReliability3.3. ValidityValidity
  17. 17. GOODNESS OF MEASURESGOODNESS OF MEASURES1.Item Analysis1.Item AnalysisIt is done to see if the items in the instrument belong there or not. EachIt is done to see if the items in the instrument belong there or not. Eachitem is examined for its ability to discriminate between those subjectsitem is examined for its ability to discriminate between those subjectswhose total scores are high, and those with low scores.whose total scores are high, and those with low scores.In item analysis, the means between the high score group and the lowIn item analysis, the means between the high score group and the lowscore group are tested to detect significant differences through the t-score group are tested to detect significant differences through the t-values.values.
  18. 18. GOODNESS OF MEASURESGOODNESS OF MEASURES2. Reliability :2. Reliability :The reliability of a measure is an indication of the stability andThe reliability of a measure is an indication of the stability andconsistency with which the instrument measures the concept and helps toconsistency with which the instrument measures the concept and helps toassess the “goodness” of a measure.assess the “goodness” of a measure.
  19. 19. GOODNESS OF MEASURESGOODNESS OF MEASURESTesting Goodness of Measures : Forms of Reliability and ValidityTesting Goodness of Measures : Forms of Reliability and ValidityGoodness ofdataValidity(are wemeasuringthe right thing)Reliability(accuracy inmeasurement)Criterion-relatedvalidityFace validity Predictive ConcurrentLogicalValidity (content)Convergent DiscriminationConcurrent validity(construct)ConsistencyStabilityInteritem consistencyreliabilitySplit-half reliabilityParallel-form reliabilityTest-retest reliability
  20. 20. GOODNESS OF MEASURESGOODNESS OF MEASURESStability of measures :Stability of measures :The ability of a measure to remain the same over time – despiteThe ability of a measure to remain the same over time – despiteuncontrollable testing conditions or the state of the respondentsuncontrollable testing conditions or the state of the respondentsthemselves- is indicative of its stability and vulnerability to changes inthemselves- is indicative of its stability and vulnerability to changes inthe situation.the situation.Test-retest Reliability :Test-retest Reliability :The reliability coefficient obtained with a repetition of the same measureThe reliability coefficient obtained with a repetition of the same measureon a second occasion is called test-retest reliability.on a second occasion is called test-retest reliability.Parallel-Form Reliability:Parallel-Form Reliability:When responses on two comparable sets of measures tapping the sameWhen responses on two comparable sets of measures tapping the sameconstruct are highly correlated, we have parallel-form reliability.construct are highly correlated, we have parallel-form reliability.
  21. 21. Internal Consistency of Measures:Internal Consistency of Measures:It is the indicative of the homogeneity of the items in the measure thatIt is the indicative of the homogeneity of the items in the measure thattap the construct.tap the construct.Interitem Consistency Reliability:Interitem Consistency Reliability:This is a test of the consistency of respondents answers to all the items inThis is a test of the consistency of respondents answers to all the items ina measure. To the degree that items are independent measures of thea measure. To the degree that items are independent measures of thesame concept, they will be correlated with one another.same concept, they will be correlated with one another.Split-Half reliability :Split-Half reliability :Reflects the correlations between two halves of an instrument. TheReflects the correlations between two halves of an instrument. Theestimates would vary depending on how the items in the measure areestimates would vary depending on how the items in the measure aresplit into two halves.split into two halves.
  22. 22. GOODNESS OF MEASURESGOODNESS OF MEASURESValidity :Validity :Ensures the ability of a scale to measure the intended concept.Ensures the ability of a scale to measure the intended concept.Internal validity – the authenticity of the cause-and-effect relationshipsInternal validity – the authenticity of the cause-and-effect relationshipsExternal validity – generalizabiltiy to the external environment.External validity – generalizabiltiy to the external environment.Content Validity:Content Validity:Ensures that the measure includes an adequate and representative set ofEnsures that the measure includes an adequate and representative set ofitems that tap the concept. The more the scale items represent the domainitems that tap the concept. The more the scale items represent the domainor universe of the concept being measured, the greater the contentor universe of the concept being measured, the greater the contentvalidity.validity.Face Validity :Face Validity : Indicates that the items that are intended to measure aIndicates that the items that are intended to measure aconcept, do on the face of it look like they measure the concept.concept, do on the face of it look like they measure the concept.
  23. 23. GOODNESS OF MEASURESGOODNESS OF MEASURESCriterion Related Validity:Criterion Related Validity:Established when the measure differentiates individual on a criterion it isEstablished when the measure differentiates individual on a criterion it isexpected to predict.expected to predict.Concurrent Validity:Concurrent Validity: Established when the scale discriminates individualEstablished when the scale discriminates individualwho are known to be different.who are known to be different.Predictive Validity :Predictive Validity : Indicates the ability of the measuring instrument toIndicates the ability of the measuring instrument todifferentiate among individuals with reference to a future criterion.differentiate among individuals with reference to a future criterion.Ex: Aptitude or ability test.Ex: Aptitude or ability test.
  24. 24. GOODNESS OF MEASURESGOODNESS OF MEASURESConstruct Validity:Construct Validity:Testifies how well the results obtained form the use of the measure fit theTestifies how well the results obtained form the use of the measure fit thetheories around which the test is designed.theories around which the test is designed.Convergent validity :Convergent validity : Established when, scores obtained with twoEstablished when, scores obtained with twodifferent instruments measuring the same concept are highly correlated.different instruments measuring the same concept are highly correlated.Discriminant Validity :Discriminant Validity : Established when, based on theory, two variablesEstablished when, based on theory, two variablesare predicted to be uncontrolled, and the scores obtained by measuringare predicted to be uncontrolled, and the scores obtained by measuringthem are indeed empirically found to be so.them are indeed empirically found to be so.Some of the ways in which the above forms of validity can beSome of the ways in which the above forms of validity can beestablished are through,established are through,1. Correlational analysis, 2.factor analysis, 3. multivariate analysis.1. Correlational analysis, 2.factor analysis, 3. multivariate analysis.

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