The construct of motivation toward school is vaguely defined. The Junior Index of Motivation (JIM Scale) is one of few instruments claiming validity in measuring motivation toward school among junior and semior high students. This study discusses the shortcomings of the JIM scale, and compares item and total score characteristics and correlates with I. Q. scores, absences and grades. On the basis of these data, current usage of the JIM Scale should proceed with caution. (Author)