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Muhammad Shafiq
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Measurement
Concept
A generalized idea about a class of objects, attributes, occurrences, or
processes
Operational Definition
Specifies what the researcher must do to measure the concept under
investigation
Media Skepticismconceptual definition
• Media skepticism - the degree to which individuals are skeptical toward the reality presented in the mass media. Media skepticism varies across individuals, from those who are mildly skeptical and accept most of what they see and hear in the media to those who completely discount and disbelieve the facts, values, and portrayal of reality in the media.
Media SkepticismOperational Definition
Please tell me how true each statement is about the media. Is it very true, not very true, or not at all true?
• 1. The program was not very accurate in its portrayal of the problem.
• 2. Most of the story was staged for entertainment purposes.
• 3. The presentation was slanted and unfair.
Scale
• Series of items arranged according to value for the purpose of quantification
• A continuous spectrum
Nominal Scale
Ordinal Scale
Interval Scale
Ratio Scale
Scale Properties
• Uniquely classifies
• Preserves order
• Equal intervals
• Natural zero
Nominal Scale Properties
• Uniquely classifies– Sammy Sosa # 21– Barry Bonds # 25
Ordinal Scale Properties
• Uniquely classifies
• Preserves order
• Win, place, & show
Interval Scale Properties
• Uniquely classifies
• Preserves order
• Equal intervals– Consumer Price Index (Base 100)– Fahrenheit temperature
Ratio Scale Properties
• Uniquely classifies
• Preserves order
• Equal intervals– Natural zero– Weight and distance
Index Measures
• ATTRIBUTES A single characteristic or fundamental feature that pertains to an object, person, or issue
• COMPOSITE MEASURE A composite measure of several variables to measure a single concept; a multi-item instrument
The Goal of Measurement Validity
Validity
The ability of a scale to measure what was intended to be measured
Reliability
The degree to which measures are free from random error and therefore
yield consistent results
Old Rifle New Rifle New Rifle Sun glare
Low Reliability High Reliability Reliable but Not Valid
(Target A) (Target B) (Target C)
Reliability and Validity on Target
Validity
F A C E O R C O N TE N T
C O N C U R R E N T P R E D IC TIV E
C R ITE R IO N V A L ID ITY C O N S TR U C T V A L ID ITY
V a lid ity
Reliability
TE S T R E TE S T
S TA B IL ITY
E Q U IV A L E N T F O R M S S P L ITTIN G H A L V E S
IN TE R N A L C O N S IS TE N C Y
R E L IA B IL ITY
Sensitivity
• A measurement instrument’s ability to accurately measure variability in stimuli or responses.
