PSYC37H3 Chapter Notes - Chapter 4: Classical Test Theory, Item Response Theory, Abraham De Moivre
Document Summary
Discrepancies between true ability and measurement of ability constitute errors of measurement. Chapter 4: reliability: error: implies that there will always be some inaccuracy in our measurements. Tests that are relatively free of measurement error are deemed to be reliable: tests that have too much measurement error are considered unreliable. Psychological measurements usually pursue complex traits such as intelligence or aggressiveness. Charles spearman advanced development of reliability assessment: reliability theory puts these two concepts together in the context of measurement: Abraham de moivre (1733) introduced sampling error. Cronbach et al. developed methods for evaluating many sources of error in behavioural research. More recently, item response theory (irt) has taken advantage of computer technology to advance psychological measurement significantly. Classical test score theory: assumes that each person has a true score that would be obtained if there were no errors in measurement: scores observed almost always differs from the person"s true ability or characteristic, symbolic formula:
