In this study, the prototype strategy was used to develop scales for the assessment of student motivation In a prestudy, teachers generated student behaviors for each pole of the motivation dimension The prototypicahty of the motivated and unmotivated behaviors for the respective poles of the dimension was rated by panels of junior high school students On the basis of these ratings, scales were constructed which differed in the mean-rated prototypicallty of their items In the mam study the validities of these scales were investigated using peer ratings and a psychometnc test as cntenon measures Using confirmatory factor analysis, it was demonstrated that, as predicted, the scales with the more prototypical items had higher validity coefficients More generally, these scales possessed satisfactory psychometnc properties Finally, the ments of the prototype strategy were discussed with respect to its contnbutions to the substantive and structural component of construct validityIn the last decade mterest in people's implicit knowledge about the world has grown In personality research, implicit theones about types of persons (