Strong Interest Inventory - History

History

Before he created the Inventory, Strong was the head of the Bureau of Educational Research at the Carnegie Institute of Technology. Strong attended a seminar at the Carnegie Institute of Technology where a man by the name of Clarence S. Yoakum introduced the use of questionnaires in differentiating between people of various occupations. This later sparked Strong's interest in developing a better way of measuring people's occupational interests. (Donnay, 1997). Starting off as the "Strong Vocational Interest Blank", the name changed when the test was revised in 1974 to the Stong-Campbell Interest Inventory. Today we call it the Strong Interest Inventory. The Inventory has been revised 6 times over the years to reflect continued development in the field. Strong based his empirical approach on the idea that interests were on a dimension of liking to disliking that could be used to discriminate among various occupational groups. (Donnay, 1997, p.3) In other words, Strong developed several scales that contrasted groups of people, based on their answers. This method of scaling, developed by Strong, has been very influential and has been used in several different questionnaires, including the Minnesota Multiphasic Personality Inventory (MMPI). Strong's original Inventory had 10 occupational scales. The original Inventory was created with men in mind, so in 1933 Strong came out with a women's form of the Strong Vocational Blank. In 1974 when the Strong-Campbell Interest Inventory came out, Campbell had combined both the men's and the women's forms into a single form. Other improvements that Campbell made to earlier versions include: the use of 124 occupational scales, the continued use of 23 Basic Interest Scales, and the addition of 2 special scales to measure academic comfort and introversion/extroversion dimensions. The Strong Interest Inventory is high in both predictive and concurrent validity (Donnay, 1997).