Asking Good Questions – Week 6
Marketers measure qualities that most do not think of in terms of measurement
- Attributes of a product
- Satisfaction with a service or product
- Likelihood of a behavior
- Predicting the next behavior
Rules for assigning numbers to objects to represent quantities of attributes
- Measure the ATTRIBUTES of an object – NOT measuring the object
- Definition is broad because
different attributes
have different qualities that
dictate the rules of
how numbers are assigned
Scales of Measurement
- Nominal Scale
- Measurement in which numbers are assigned to objects or classes of objects solely for the purpose of identification
- Gender: 1=Female, 2=Males
Ordinal Scale
- Measurement in which numbers are assigned to data on the basis of some order (e.g., more than, greater than) of objects
- Also take on the properties of nominal scale (identification)
- Brand Preference: Rank the following mascara brands (1=Most preferred, 4=Least preferred)
__ Coke
__ Pepsi
__ Mountain Dew
__ 7 Up
Interval Scale
- Measurement in which the assigned numbers legitimately allow the comparison of the size of the differences among and between numbers
- Also take on the properties of nominal (identification) and ordinal (rank order) scales
- Brand Attitude: What is your feeling toward each of the following mascara brands (1=Negative, 5=Positive)?
Coke 1 2 3 4 5
Pepsi 1 2 3 4 5
Moutain Dew 1 2 3 4 5
7 Up 1 2 3 4 5
Ratio Scale
- Measurement that has a natural, or absolute, zero and therefore allows the comparison of absolute magnitudes of the numbers
- Also take on the properties of nominal (identification), ordinal (rank order), and interval (rating) scales
- Units Sold: How many of each of the following sodas did you consume in the last week?
Coke _____ sodas
Pepsi _____ sodas
Moutain Dew _____ sodas
7 Up _____ sodas
How can attitudes, perceptions, and preferences be measured?
- Most of the time they are assessed via respondent self-reports
- A communication method is employed and respondents are asked for their evaluations (i.e., attitudes) with regard to an attitude object
- Two most common scale types are both at the interval level of measurement
- Summated-Rating (Likert) Scale
- Semantic-Differential Scale
Other Considerations
- Number of Items in a Scale
- The four previous examples had four items (i.e., questions) each
- Could a global measure (e.g., an overall evaluation) have provided the same insight?
- Number of Scale Positions
- The Summated-Rating and Semantic-Differential examples had five scale positions each
- Would six have been better? Seven?
Including a “Don’t Know” or “Not Applicable” Response Category
- If you are unfamiliar with First National Bank and its attributes, would the opportunity to state that these questions do not apply be helpful?
Reverse Scaling
- The Summated-Rating example had positively worded items
- Positive: courteous service, convenient location, convenient hours, low-interest rate loans
- What if we used negatively worded items?
- Negative: discourteous service, inconvenient location, inconvenient hours, high-interest rate loans
Errors
- Systemic Error or constant error – error the impacts the measurement in a consistent manner
- Responses concerning satisfaction are consistently higher when taken via phone interview compared to email.
- Random Error – error due to temporary aspects of a person’s situation
- Based on mood, fatigue or most recent encounter.
Validity and Reliability
- Higher the errors – Lower Validity – Less Reliable
- Lower the errors – Higher Validity – More Reliable