If you’re considering retaking the GMAT, you’re not alone.  Nearly 20 percent of the thousands of GMATs proctored each year are given to people who have attempted the exam at least once before.

The reasons for trying again are many.  Perhaps your first exam resulted in a score lower than you expected after months of studying and high marks on practice tests, or perhaps you hardly studied at all, expecting all along to take the test more than once.

Taking the test at least twice has become as much of a strategy as it is a necessity for many test takers, especially as many management programs will now aggregate your best scores across all your tests.  Despite the commonality of taking multiple exams, questions remain about the advantages and gains of taking the GMAT more than once.

GMAT score improvement: common but meager

The good news for anyone contemplating taking the GMAT again is that most people do improve their scores.  However this improvement is relatively minor.  According to GMAC data, on their second GMAT, most testers increased their total score by an average of 33 points.  A sizable 25 percent of these testers who took the GMAT a second time scored lower.

Furthermore, the amount of  improvement made by re-testers has been shown to be inversely related to their original scores.  In other words, the lower a person’s score on their first test, the greater the improvement they generally made on their second GMAT test, and conversely, the higher a person’s first GMAT score, the lower their average improvement was on a second test.

In the data, testers who scored well below average on their first test — a total GMAT score between 200 and 490 — increased their score by an average of 45 points on their second test.  Contrast this with testers who scored in the top percentiles, between 700 and 800 points on their first GMAT: They only improved their total score by an average of 5 points on their second attempt.  For everyone else who scored in the mid-range on their first GMAT, average improvements ranged from 33 points for those who scored in the 500s to 20 point improvements for those who scored in the 600s originally.

One reason for this drastic difference in average improvement is what the GMAC calls “baseline tests.”  In some instances, students will take their first GMAT without studying, using the results as a baseline by which to gauge their abilities before studying and then taking the test again.  Because of this, average improvements are likely biased, especially for lower first scores as they show more improvement than what may be reasonably expected by someone who studied for their first test.

Another factor in this trend is that improvement becomes more difficult the higher you score.  While improving a low score may be straightforward — for example, improving time management or accounting for a significant gap in knowledge — improving a good score is more challenging.  Answering difficult questions correctly takes a more nuanced understanding of the concepts and how the GMAT tests them.

What this means for your GMAT score

These statistics may be disheartening by dashing your hopes for a dramatic improvement in your score, but for many people, taking the GMAT a second or third time still makes sense.  There’s a decent chance that taking the GMAT again will result in a higher score, and depending on the competitiveness of your original score, even a modest gain can make a significant difference.  Also the data says nothing about how the average tester prepares for a second or third GMAT exam.  Time and time again, testers do make large increases in their GMAT score after revamping their study tactics.

However, if you scored 700 or above on your first test, your time may be better spent working on your application.  Unless you’re committed to making a large effort for what’s likely an inconsequential gain, fine tuning your admission essays and other application materials will better aid your admission chances.

Are you contemplating taking the GMAT again or have already taken it a few times?  Share your experiences by leaving a comment below.