How is the New GRE Scored?
July 13, 2012
As a GRE instructor and tutor, I’ve heard lots of “theories” about how the new GRE is scored. Because the scoring formula is not terribly well-defined by ETS, it’s completely normal for people to have questions or concerns about how their final GRE scaled score is calculated.
First of all, the test is no longer a Computer Adaptive Test, or CAT, which was the format of the test from 1992 through August 2011.
- One of the frustrating aspects of the Computer Adaptive Test was that whenever you were presented with a question, you had to answer it before moving on. This was because of the adaptive nature of the test; since the next question in a section relied on your performance of the questions that came before it, there was no opportunity to skip a question.
- Another frustrating element of the CAT was the apparent disconnect between “raw scores” and scaled scores. The raw score of a test is defined as the number of questions a GRE test-taker answers correctly, while the scaled score is the score that conforms to a fabricated scale. To demonstrate, let’s take a look at a scenario that happened often on the old GRE. On that test, the Math and Verbal sections only had 30 questions each, and the scaled scores for each section ranged from 200-800. And let’s imagine that you and a friend both answered 20 out of 30 questions correctly in the Verbal section, giving you each a raw score of 20. But your scaled score was 600 and your friend’s scaled score was 650. What? How does that work? Well, remember: because it was an adaptive test, you and your friend were being presented with different questions. Your friend probably answered more questions correctly at the beginning of the test and was then given more difficult questions later on, while you probably did a little worse at the beginning and were then given less difficult questions at the end of the test. How exactly the algorithm worked to determine a scaled GRE score from various raw scores was always a little bit of a mystery, but typically the test scored you by how difficult the questions were at the end of your test.
The new GRE a Multi-Stage Test, or MST. Here are some MST facts:
- In this format, test-takers are evaluated on their performance on two separate Quantitative and Verbal sections, or stages.
- The test adapts from section to section.
- The scaled score on the new GRE ranges 40 points (from 130 to 170)
While each individual stage of the GRE is comprised of 20 questions that are not adaptive, the test is not the same for all test-takers. That’s because depending on a test taker’s performance in the first stage, the second stage (also 20 questions) will be either low difficulty, average difficulty, or high difficulty. This presents us with a similar problem to the old CAT – if test-takers are being presented with questions of varying difficulty, then how can we reliably convert raw scores to scaled scores? The answer is: okay, well, to be honest, the answer is that it’s pretty tough.
Now, it may be tempting to infer (and lots of students do) that because the scaled score on the new GRE ranges 40 points (from 130 to 170), and because there are 40 total questions in each content area, the scaled score tacks up one point for every correct answer chosen. Although that’s close to what’s going on, it’s not entirely accurate. Because the second section varies in difficulty, raw scores are not directly tied to scaled scores. Instead, the test looks at not only the number of questions you answered correctly, but also at how difficult those questions were. The test-makers call this equating, and they briefly describe it on their website: “The raw score is converted to a scaled score through a process known as equating. The equating process accounts for minor variations in difficulty among the different test editions as well as the differences in difficulty introduced by the section-level adaptation. Thus a given scale score reflects approximately the same level of performance regardless of which second section was selected and when the test was taken.” (Source: http://www.ets.org/gre/revised_general/scores/how)
So, just like with old GRE test format, there is an element of unknowing here. The ETS has their own special sauce that they use to evaluate raw scores, and because of that, there is a not a completely linear 1:1 fit between raw and scaled scores. But that doesn’t mean we don’t know anything about how the new test is scored. For one thing, we do know that it is very important to score well in the first stage of both the Quantitative and Verbal sections. This is necessary in order to bump you up to the medium or high difficulty second section, where you can begin to separate yourself from the bottom third of test-takers. Here’s a visual breakdown of how it works:
Additionally, because each section is only 40 questions, answering just two or three more questions correctly can mean a big jump in percentile rank. Here is a concordance table released by the test-makers that shows the relationships between old scaled scores, new scaled scores, and percentile ranks: http://www.ets.org/s/gre/pdf/concordance_information.pdf . If you look at Verbal scaled scores on the new test, a 150 is the 48th percentile while a 153 is the 62nd percentile. By answering (roughly) three more questions correctly, you can jump over 14% of test-takers.
At the end of the day, worrying about how the test is scored only gets you so far. While it is definitely helpful to know how the test is scaled, what raw score targets you should be aiming for, and how your scaled score compares to other test-takers, the most important thing you should be focusing on in your prep is how to improve your current score. The more practice MSTs you take, the more of a feel you’ll get for how many questions you need to answer correctly to hit your target score. And once you’re consistently answering enough questions to hit that target score, my advice would remain the same – keep practicing and working to raise your score even more. In all my years of teaching and tutoring, I’ve yet to have a student complain because they improved so much they surpassed their target score.
Now that you have a better idea of how the Multi-Stage GRE is scored and scaled, it’s time to get back to studying. If you have any questions, please don’t hesitate to ask in the comments below!