PSYC37H3 Chapter Notes - Chapter 4: Item Response Theory, Classical Test Theory, Reliability Engineering
22 Feb 2019
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Measurement task is more difficult in psych than in physical science. Pursuing complex traits like intelligence that you can"t see or touch need very reliable tests to be able to do this well enough. Theory of measurement error is well developed within psych. Reliability theory puts together sampling error and product moment correlation in the context of measurement. Responsible for advanced development of reliability assessment created contemporary reliability theory. Thorndike used his work too and he was a measurement pioneer. Cronbach major advance by developing methods for evaluating many sources of error in behavioural research. Classic test score theory assumes that each person has a true score that would be obtained if there were no errors in measurement but score that we actually obtain differs from their true ability. Observed score has 2 components true score and error component: x (observed score) = t (true score) + e (error) Major assumption is that errors of measurement are random.
