In: Historical Events

Submitted By captain32
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Pages 3
What is Reliability? * Consistency * It is not a characteristic of the test but a property of the scores obtained when the test is administered to a particular group of people on a particular occasion under specific conditions * Not the same thing as stability
Classical Reliability Theory * By Charles Spearman (1904) * Also called the Theory of true and error scores * It assumed that a person’s observed score on a test is composed of a “true” score plus some unsystematic error of measurement * TRUE SCORE – the average of the scores a person would obtain if he/she took the test an infinite number of times
2 Factors that influence test scores: * 1. Factors that contribute to consistency - consist of those stable attributes of the individual which the examiner is trying to measure (TRUE VARIANCE) * 2. Factors that contribute to inconsistency – these include the characteristics of the individual, test, or situation which have nothing to do with the attribute being measured but affects the scores (ERROR VARIANCE)
* X = T + e * Where: * X is the obtained score * T is the true score * e is the errors of measurement * Errors in measurement –represent discrepancies b/n obtained scores and the corresponding true scores (E=X – T)
SOURCES OF MEASUREMENT ERROR (ERROR VARIANCES) * Item Selection(Intrinsic Error Variance) * Found in the instrument itself * Test items may not be equally fair to all persons * There maybe intrinsic elements of chance within the score of the testee * By accident, he/she knew items by chance or he/she does not know the items * 2. Extrinsic Error Variances (Internal or External)
A. Test Administration * Physical structure of the room * Motivation of the examinees * Style of the examiner
B. Test Scoring

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