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Measurement and Scaling. Chapter 6. Learning Objectives : Understand the role of concepts in business research. Explain the notion of measurement. Provide an overview of the types of measurement scales. Distinguish between reliability and validity. What is a concept?.
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Measurement and Scaling Chapter 6 Learning Objectives: • Understand the role of concepts in business research. • Explain the notion of measurement. • Provide an overview of the types of measurement scales. • Distinguish between reliability and validity.
What is a concept? A concept is a mental abstraction or idea formed by the perception of some phenomena. Examples of concepts in business include job satisfaction, job commitment, brand awareness, brand loyalty, service quality, image, risk, channel conflict, empathy, and so on.
12 Dimensions of a Great Workplace Go On-Line www.gallup.com Item 1. I know what is expected of me at work. Item 2. I have the materials and equipment I need to do my work right. Item 3. At work, I have the opportunity to do what I do best everyday. Item 4. In the last seven days, I have received recognition or praise for doing good work. Item 5. My supervisor, or someone at work, seems to care about me as a person. Item 6. There is someone at work who encourages my development. Item 7. At work, my opinions seem to count. Item 8. The mission or purpose of my company makes me feel my job is important. Item 9. My fellow employees are committed to doing quality work. Item 10. I have a best friend at work. Item 11. In the last six months, someone at work has talked to me about my progress. Item 12. This last year, I have had opportunities at work to learn and grow.
Measurement . . . involves assigning numbers to a variable according to certain rules that reflect the characteristics of the phenomenon being measured.
What is the measurement process? The measurement process involves specifying the variables that serve as proxies for the concepts (constructs). A proxy is a variable that represents a single component of a larger concept and, taken together, several proxies (indicator variables) are said to measure a concept.
Scale . . . a scale is a measurement tool that can be discrete or continuous. Discrete scales measure only direction, but continuous scales measure both direction and intensity.
Four Levels of Measurement Ratio ? Interval Ordinal Nominal
Types of Scales Metric Scales • Summated Ratings • Numerical • Semantic Differential • Graphic Ratings Nonmetric Scales • Categorical • Rank Order • Sorting • Constant Sum • Paired Comparison
Summated Ratings Scale Gino’s Italian Ristorante has a wide variety of menu choices. Strongly Disagree Neither Agree Agree Strongly Disagree nor Disagree Agree 1 2 3 4 5
Numerical Scale Using a 10-point scale, where 1 is “not at all important” and 10 is “very important” how important is ________ in your decision to do business with a particular vendor?
Semantic Differential Scale “My supervisor is . . . . “ Courteous ___ ___ ___ ___ ___ Discourteous Friendly ___ ___ ___ ___ ___ Unfriendly Helpful ___ ___ ___ ___ ___ Unhelpful Supportive ___ ___ ___ ___ ___ Hostile Competent ___ ___ ___ ___ ___ Incompetent Honest ___ ___ ___ ___ ___ Dishonest Enthusiastic ___ ___ ___ ___ ___ Unenthusiastic
Graphic Ratings On a scale from 0 to 10 how would you rate the atmosphere of Samouel’s Greek Cuisine restaurant? Indicate by placing an “X” at the appropriate place on the line. Poor OK Excellent |____________________|____________________| 0 5 10
Categorical How satisfied are you with your current job? [ ] Very Satisfied [ ] Somewhat Satisfied [ ] Neither Satisfied nor Dissatisfied [ ] Somewhat Dissatisfied [ ] Very Dissatisfied How interested are you in learning more about the benefits that are offered with this health plan? [ ] Very Interested [ ] Somewhat Interested [ ] Not Very Interested
Sorting This type of scaling approach asks respondents to indicate their beliefs or opinions by arranging objects (items) on the basis of perceived similarity, preference, or some other attribute.
Criteria for Assessing Measurement Scales Go On-Line www.raosoft.com Reliability Validity
Practical Decisions When Developing Scales Number of Scale Categories Number of Items to Measure a Concept Odd or Even Number of Categories Balanced of Unbalanced Scales Forced or Non-forced Choice Category Labels for Scales
Balanced vs. Unbalanced Scales “To what extent do you consider TV shows with sex and violence to be acceptable for teenagers to view?” Balanced: __ Very Acceptable __ Somewhat Acceptable __ Neither Acceptable or Unacceptable __ Somewhat Unacceptable __ Very Unacceptable Unbalanced: __ Very Acceptable __ Somewhat Acceptable __ Unacceptable
Forced or Non-Forced? “How likely are you to purchase a laptop PC in the next six months?” Very Very Unlikely Likely ___ No 1 2 3 4 5 6 Opinion
Category Labels for Scales? Verbal Label: “How important is the size of the hard drive in selecting a laptop PC to purchase?” Very Somewhat Neither Important Somewhat Very Unimportant Unimportant or Unimportant Important Important 1 2 3 4 5 Numerical Label: “How likely are you to purchase a laptop PC in the next six months?” Very Very Unlikely Likely 1 2 3 4 5 Unlabeled: “How important is the weight of the laptop PC in deciding which brand to purchase?” Very Very Unimportant Important ___ ___ ___ ___ ___
Choosing a Measurement Scale • Capabilities of Respondents • Context of Scale Application • Data Analysis Approach • Validity and Reliability
Assessing Measurement Scales: • Validity • Reliability Measurement Error = occurs when the values obtained in a survey (observed values) are not the same as the true values (population values).
Reliability • Test-retest • Alternative Forms • Internal Consistency
Exhibit 6-5 Rules of Thumb about Cronbach’s Alpha Coefficient Size Coefficient Strength of Range Association < .6 Poor .6 to < .7 Moderate .7 to < .8 Good .8 to < .9 Very Good > = .9 Excellent
Validity • Content • Construct • Convergent • Discriminant • Criterion • Concurrent • Predictive
Multi-Item Scales Go On-Line www.burke.com
Scales – used to measure concepts (constructs). Two Options: Use published scales. Develop original scales.
Steps in Developing a Scale: • Definition of the concept(s) to be measured. • Identification of the components of the concept. • Specification of a sample of observable and measurable items to represent the components. • Selection of the appropriate scales to measure the items. • Combination of the items into a composite scale to measure the concept. • Administer the scale to a sample and assess respondent understanding. • Revise the scale as needed.
Measurement and Scaling Go On-Line www.sric-bi.com How does this website help you to better understand measurement and scaling?
Measurement and Scaling Go On-Line www.icpsr.umich.edu/gss What kinds of scales are used on the General Social Survey on this Website?