Measurement is the process of assigning numbers or labels to objects, persons, states, or events in accordance with specific rules to represent quantities or qualities of attributes.
We do not measure specific objects, persons, etc., we measure attributes or features that define them.
Ex., What defines the person Brent Wren? What is a student’s level of education? How customer oriented is our company?
Overriding Goal: To provide a valid and reliable description or enumeration of the person, objects, issue, etc.
The generation of a continuum upon which measured objects are located.
Scale
A quantifying measure – a combination of items that is progressively arranged according to value or magnitude.
Purpose is to quantitatively represent an item’s, person’s, or event’s place in the scaling continuum.
Some Key Concepts
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Four Basic Scales of Measurement Nominal Scales Ordinal Scales Interval Scales Ratio Scales
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Primary Scales of Measurement Bob Gene Sam Scale Nominal Symbols Assigned to Runners Ordinal Rank Order of Winners Interval Performance Rating on a 0 to 10 Scale Ratio Time to Finish, in Seconds Finish Finish 3 7 9 15.2 14.1 13.4 3 rd place 2 nd place 1 st place
A ranking scale in which numbers are assigned to objects to indicate the relative extent to which the objects possess some characteristic.
Can determine whether an object has more or less of a characteristic than some other object, but not how much more or less.
Any series of numbers can be assigned that preserves the ordered relationships between the objects.
In addition to the counting operation allowable for nominal scale data, ordinal scales permit the use of statistics based on centiles, e.g., percentile, quartile, median.
Numerically equal distances on the scale represent equal values in the characteristic being measured.
It permits comparison of the differences between objects. For example, the difference between 1 and 2 is the same as between 3 and 4. The difference between 1 and 9 (i.e., 8) is twice as large as the difference between 2 and 4 (i.e., 2) or 6 and 8 (2).
The location of the zero point is not fixed. Both the zero point and the units of measurem. are arbitrary.
It is NOT meaningful to take ratios of scale values
It IS meaningful to take ratios of their differences.
Statistical techniques that may be used include all of those that can be applied to nominal and ordinal data, and in addition the arithmetic mean, standard deviation, correlation, and other common statistics.
Possesses all the properties of the nominal, ordinal, and interval scales.
It has an absolute zero point. Examples: height, weight, age, money, sales, costs, market share, number of customers, the rate of return.
It is meaningful to compute ratios of scale values.
For example, not only is the difference between 2 and 5 the same as the difference between 14 and 17, but also 14 is seven times as large as 2 in an absolute sense.
All statistical techniques can be applied to ratio data.
Respondent is presented with two objects at a time
Then asked to select one object in the pair according to some criterion
Data obtained are ordinal in nature
Arranged or ranked in order of magnitude
Easy to do if only a few items are compared.
If number of comparisons is too large, respondents may become fatigued and no longer carefully discriminate among them.
Paired Comparison Scaling
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Paired Comparison Scaling: Example For each pair of professors, please indicate the professor from whom you prefer to take classes with a 1. Cunningham Day Parker Thomas Cunningham 0 0 0 Day 1 1 0 Parker 1 0 0 Thomas 1 1 1 0 # of times preferred 3 1 2 0
Respondents are presented with several objects simultaneously
Then asked to order or rank them according to some criterion.
Data obtained are ordinal in nature
Arranged or ranked in order of magnitude
Commonly used to measure preferences among brands and brand attributes
Rank Order Scaling
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Rank Order Scaling Please rank the instructors listed below in order of preference. For the instructor you prefer the most, assign a “1”, assign a “2” to the instructor you prefer the 2 nd most, assign a “3” to the instructor that you prefer 3 rd most, and assign a “4” to the instructor that you prefer the least. Instructor Ranking Cunningham 1 Day 3 Parker 2 Thomas 4
Respondents are asked to allocate a constant sum of units among a set of stimulus objects with respect to some criterion
Units allocated represent the importance attached to the objects.
Data obtained are interval in nature
Allows for fine discrimination among alternatives
Constant Sum Scaling
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Constant Sum Scaling Listed below are 4 marketing professors, as well as 3 aspects that students typically find important. For each aspect, please assign a number that reflects how well you believe each instructor performs on the aspect. Higher numbers represent higher scores. The total of all the instructors’ scores on an aspect should equal 100. Instructor Availability Fairness Easy Tests Cunningham 30 35 25 Day 30 25 25 Parker 25 25 25 Thomas 15 15 25 Sum Total 100 100 100
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A Classification of Scaling Techniques Likert Semantic Differential Stapel Scaling Techniques Noncomparative Scales Comparative Scales Paired Comparison Rank Order Constant Sum Q-Sort and Other Procedures Continuous Rating Scales Itemized Rating Scales
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Continuous Rating Scale Example Very Poor Very Good 0 10 20 30 40 50 60 70 80 90 100 X
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Likert Scale A likert scale is an ordinal scale format that asks respondents to indicate the extent to which they agree or disagree with a series of mental or behavioral belief statements about a given object
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Semantic Differential Scale A semantic differential scale is unique bipolar ordinal scale format that captures a person’s attitudes and/or feelings about a given object
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Behavioral Intention Scale A behavioral intention scale is a special type of rating scale designed to capture the likelihood that people will demonstrate some type of predictable behavior intent toward purchasing an object or service in a future time frame
In order for a scale to valid, it must also be reliable.
In other words,
Reliability is a necessary but insufficient condition for Validity.
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Reliability and Validity on Target Old Rifle New Rifle New Rifle Sunglare Low Reliability High Reliability Reliable but Not Valid (Target A) (Target B) (Target C)
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