Chapter 10 Marketing Research
Discrete Measures
-common scales include any yes-no response, matching, etc. -can possess ordinal properties and nominal properties -this measure is best captured by the mode (most often)
Internal Consistency
-represents a measure's homogeneity
Abstract Properties
Are more difficult to both define and measure. Ex: brand loyalty, personality, etc.
(4) Levels of Scale Measurement
Nominal Ordinal Interval Ratio
An Attribute
a single characteristic or fundamental feature of an object, person, situation, or issue.
Concepts
generalized ideas that represent something of meaning.
Index Measures or Composite Measures
multi-item instruments for measuring a construct.
Operational Definitions
researchers measure concepts through a process known as operationalization.
Interval Scales
-Have both nominal and ordinal properties -capture information about differences in quantities of a concept -do not exactly represent some phenomenon
Criterion Validity
-addresses the question: "Does my measure correlate with measures of similar concepts or known quantities?" -may be classified as either concurrent validity or predictive validity
Test-retest reliability
-administering the same scale or measure to the same respondents at two separate times to test for stability -represents a measure's repeatability -reliability is a necessary but insufficient condition for validity (a reliable scale may not be valid, a reliable but invalid instrument will yield consistently inaccurate results)
Ordinal scales
-allow things to be arranged based on how much of some concept they possess. -include ranking scales -horse races ex: 1st, 2nd, 3rd place
Index Measure
-assigns a value based on how much of the concept being measured is associated with an observation -often formed by putting several variables together
The Split-half method
-checks reliability -take half the items from the scale and checking them against the results from the other half -the half should: 1) correlate highly 2) produce similar scores
Reliability
-indicator of a measure's internal consistency -is reliable when different attempts at measuring something converge on the same result -when the measuring process provides reproducible results, the measuring instrument is reliable.
Ratio Scales
-represent the highest form of measurement -have all the properties of interval scales with addition to representing absolute quantities. -represent absolute meaning -provide iconic measurement -Ex: money is a way to measure economic value
Nominal Scales
-represent the simplest type of scale -assign a value to an object for identification or classification purpose -arbitrary in the sense that each label can be assigned to any of the categories without introducing error. -Ex: uniform numbers, airport terminals, school bus numbers
Coefficient Alpha
-represents internal consistency by computing the average of all possible spilt-half reliabilities for a multiple item scale. -ranges in value 0 (no consistency) 1 (complete consistency) Ex: 0.80- 0.96 very good reliability 0.70-0.80 good reliability 0.60- 0.70 fair reliability below 0.60 poor reliability
Validity
-the accuracy of a measure or the extent to which a score truthfully represents a concept. -good measures should be both precise (reliable) and accurate (valid)
Three approaches to establishing Validity
1. face content 2. criterion 3. construct
Measurement
The process of describing some property of a phenomenon of interest usually by assigning numbers in a reliable and valid way.
Operationalization
a process that involves identifying scales that correspond to variance in the concept.
Constructs
a term used for concepts that are measured with multiple variables. Operational definitions translate conceptual definitions into measurement scales.
Composite Scales
assign a value based on a mathematical derivation of multiple variables
Continuos Measures
assign values anywhere along some scale range in a place that corresponds to the intensity of some concept. -include ratio measures and interval measures
Variables
captures different concept values and scales capture variance in concepts.
Interval scales with five or more categories as:
continuous measures
Concrete Properties
present few problems in either definition or measurement. Ex: age, sex, and number of children
Face (content) Validity
refers to the subjective agreement among professionals that a scale logically reflects the concept being measured.