2 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:
3 Scales of Measurement Ratio Interval Ordinal Nominal HIGHERHigher levels of measurement have all the properties of lower levels of measurement.
4 NOMINAL SCALE: measurement in which numbers are assigned to objects solely for the purpose of identificationBasic Measures ofComparisons Examples AverageIdentity male-female mode (themost frequentlyoccurring category)user-nonuseroccupationsWhich of the following soft drinks do you like? Check all that apply. Coca-Cola Mountain Dew Seven Up Dr. Pepper Pepsi Sprite
5 Comparisons Examples Average Order brand preference median Ordinal Scale: measurement in which numbers are assigned to data on the basis of some order (more than, greater than) of the objectsBasic Measures ofComparisons Examples AverageOrder brand preference mediansocial classhardness of mineralslumber quality gradesRank the following soft drinks from 1 (least liked) to 6 (most liked):___Coca-Cola ___Mountain Dew ___Seven Up___Dr. Pepper ___Pepsi ___Sprite
6 Comparisons Examples Average Comparison temperature mean Interval Scale: measurement in which the assigned numbers allow the comparison of the size of the differences among and between numbersBasic Measures ofComparisons Examples AverageComparison temperature meanof intervals grade point avg.brand attitudecompany imageWhat is your overall opinion about each of these brands?unfavorable favorableCoca-ColaDr. PepperPepsiSprite
7 Comparisons Examples Average Comparison units sold geometric 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.Basic Measures ofComparisons Examples AverageComparison units sold geometricof absolute # of purchases meanmagnitudes ageincomeDivide 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
8 Methods for Assessing Attitude Observation of BehaviorAIndirect Techniques (projective methods)Performance of Objective TasksSelf-Report TechniquesPhysiological Reactions(Voice-pitch, galvanic skin response)
9 Measuring Attitudes and Other Unobservable Concepts 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 Scales2. Graphic-Ratings Scales3. Comparative-Ratings Scales
10 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.
11 Example of Likert (Summated-Ratings) Scale NeitherAgree norDisagreeStronglyDisagreeDisagreeAgreeStronglyAgreeThe 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.
12 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.Not Somewhat Fairly Extremely Important Important Important ImportantSound QualityPhysical SizeBrand NameDurability
13 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.
14 Example of Semantic-Differential Scale Le Bron – NikeTiger Woods – NikeKnowledgeableNot:Not ExpertExpertAttractiveUnattractiveTrustworthy
16 2. Graphic rating scalesRaters indicate their rating by placing a check at the appropriate point on a line that runs from one extreme of the attribute to the otherThe score is assessed by measuring the length of the line from one end to the marked position
17 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 Important ImportantSound QualityPhysical SizeBrand NameDurability
18 Comparative Rating Scale Respondents are asked to judge each attribute with direct reference to the other attributes being evaluated
19 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 QualityPhysical SizeBrand NameDurabilitypoints
20 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?
21 Interpreting Rating Scales: Raw Scores vs. Norms 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.
22 Interpreting Rating Scales: Raw Scores vs. Norms Population-based norms give meaning to scores by comparing them to scores obtained by similar entitiesTime-based norms track scores for an entity over time and they are useful for tracking progress and identifying problem area
23 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 attentionNumber of Items in a ScaleIf 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 itemsNumber of Scale PositionsScales with 5-9 positions are used routinely in marketing researchIncluding 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 studyDetermining Which Type of Scale to UseLet common sense guide your choice. Some cultures may not be familiar with these scales.
24 Establishing the Validity and Reliability of Measures
25 SYSTEMATIC ERROR RANDOM ERROR Error 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.
27 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.
28 Unreliable Reliable Reliable Not Valid Not Valid Valid
29 A measure can be reliable but not valid A measure can be reliable but not valid. A valid measure must be reliable.