Chapter 2 · Survey: Measurement and Scaling · Slide 73/274
The True-Score Model
The result of a measurement is not the true value of a characteristic, but only an observation of it.
2.5 · Reliability and Validity
Basic model of measurement
The True-Score Model
The result of a measurement is not the true value of a characteristic, but only an observation of it.
XOobserved
=
XTtrue
+
XSsystematic
+
XRrandom
XOobserved value of a characteristic
XTthe true value of the characteristic
XSsystematic error
XRrandom error
QUESTIONSTAR · Dr. Paul Marx
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