Measurement myths and misconceptions

This study presents some frequently encountered measurement misconceptions and various measurement "rules." Included are four misconceptions pertaining to the estimation of validity and reliability, and six rules often used during instrument development. Of these six, two pertain to the estimation of internal consistency reliability and item analysis, and four pertain to factor analysis. Whenever possible, the origins of the misconceptions and rules are described, along with the reasons why they are problematic. Alternate approaches or considerations also are given. When estimating validity and reliability, researchers are encouraged to be "ruled" by logical and critical evaluation of data rather than by arbitrary rules.