|
By Lawrence M. Rudner
GMAT Quantitative and Verbal scores range from 11 to 51, GMAT Total from 200 to 800, and Analytic Writing Assessment scores from 0 to 6.0. Where did these scales come from? What do they mean? How do the scales relate to percentiles? How do I use these numbers and percentile scores? The answers to these important questions lie in understanding the purposes of these scales.
The GMAC scale scores represent the same ability level over time. Thus, a Quant score of 43 in 2002 represents the exact same level of ability as a Quant score of 43 does in 2011. This scale consistency is a critical attribute for any test that has multiple forms, or versions, because without it, scores across forms cannot be compared. As a computer adaptive test, the GMAT exam provides every test taker a different set of questions. GMAC then has to map responses from all these different forms to the same scale. The mapping takes into account both the difficulty of each question asked and whether the test taker answered it correctly.
But, how did GMAC pick the actual numbers for the GMAT scales? In the physical sciences, there is often a meaningful zero, so it makes sense to include zero in a scale of measurement. But in mental measurement, the zero point is difficult─if not impossible─to define, so zero is rarely used in educational and psychological measurement. Some faculty members might disagree, but there’s no definition of zero ability to succeed in management education. Therefore, it makes no sense to have a zero scaled score. The 0 in the AWA assessment is not a score – it indicates that the test taker skipped the essay section.
|
