To date, one psychometric measurement instrument has been constructed
that attempts to measure the five motivational concepts of the theory.
Barbuto and Scholl (1998) developed an instrument to measure the five
motivational sources described in the meta-theory of motivation. This instrument
is known as the Motivation Sources Inventory (MSI; Barbuto & Scholl,
1998).The inventory is comprised of five subscales, each containing six items
relating to each of the five motivational sources of Leonard et al.’s (1999)
meta-theory. As reported by Barbuto and Scholl, the goodness of fit for the
five subscales was reported at .92, while the alpha coefficients of the scales
ranged from an acceptable .83 to .92. These results show support for the five
1568 JAMES C. RYAN
motivational concepts, as distinct factors that can be operationalized and
measured.