By Lawrence M. Rudner

(The first of a series of occasional articles taking a peek under the hood of the GMAT, this first installment looks at the test development process.)

How does GMAC determine the mix of skills to include on the GMAT exam? It’s a critical question because any test is defined by the skills it measures. The wrong mix can result in a test that might be reliable, but not necessarily valid.

For more than 50 years, the GMAT has been an admissions test created for business schools, by business schools. The exam has evolved continually over the years, but one constant is that defining the skills business schools expect of incoming students drives the entire test development process.

We have conducted three major curriculum surveys of business school faculty in the past five years, two global and one specifically emphasizing the curriculum in European business programs. The most recent one, in 2008, surveyed 750 leading business school faculty worldwide. Such periodic curriculum surveys have ensured that the test has aligned with business school needs though nine iterations of the exam and are also guiding the design the 10th Generation GMAT, slated for release by 2013.

The survey design process for each study began by examining current graduate course requirements, syllabi, and textbooks for MBA programs, Executive MBA programs, MA programs and European MSc programs. Requirements differ by program type, but curriculum has clearly changed over the past 10 years, with an increased emphasis on international issues and on quantitative skills. The question, then, is whether these changes warrant changes in the GMAT mix or possibly the inclusion of new skills.

From these curriculum studies, a team of content experts interviewed faculty members and generated a very broad list of skills potentially needed as entry skills for the core courses. Some skills on this initial list came directly from syllabi and some from the GMAT test specifications, but most came from an analysis of the curriculum.