PSYC 2P25 Lecture Notes - Lecture 2: Internal Consistency, Trait Theory, Convergent Validity
9 Nov 2012
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Document Summary
A measurement is reliable if it agrees with other measurements of the same variable. When scores on a measurement are calculated as a sum (or mean) of various parts ( items ) Scores should depend strongly on the common element of the items. Indicates the extent to which scores represent the common element of the items. How to make measurements have higher internal-consistency reliability: Include lots of items adding many items together gives better measurement of their common characteristic: any single item has its own specific element but when we combine items, these specific parts get cancelled out. Include items that are correlated with each other items that correlate strongly with each other are measuring a common characteristic. If items are uncorrelated with each other, they don"t have a common characteristic might be measuring several different characteristics instead. When a characteristic is measured by obtaining ratings made by several persons.
