A very common question from students preparing for Step 1 is how to use the NBME self-assessment forms that are also known as the CBSSA (Comprehensive Basic Science Self Assessment) exams on the NBME website. In addition, students want to know when to take the practice exams, and which of the self-assessments are more representative of the actual USMLE exam. We will try to answer some of these questions for you in this column and follow up next week with additional information.
- There are 7 forms with 200 multiple-choice items each.
- The assessments are $50 each at this time.
- Item formats are similar to those used on Step 1.
- Some forms have an expanded feedback; these forms are more expensive. ($60).
- Each form is divided into four sections with 50 questions each.
- You are allowed up to 1 hour to complete each section if you take the exam under “Standard Conditions” rather than “Self-Paced”.
Students are much better off taking the self-assessments under timed, standard conditions and receiving feedback. If a student wants to take questions in self-paced mode, it might be better to use a question bank or book of questions that is less expensive.
Which exams are the most like the actual USMLE exam??
According to the majority of students in 2009-2010 the:
- NBME self-assessment 7, 11,12 are more difficult
- NBME self-assessment 3, 5, 6 are easier
Which NBME self-assessments will be a closer representation to the USMLE Step 1? This is a very common question and a good question. However, the truth may be that the self-assessment that is closest will depend on the exam you end up with on the day you sit for Step 1. Because different exam content is generated for the different USMLE testing sessions, students have historically reported several experiences ranging from:
- “My Step 1 exam look just like Kaplan Q Bank” (or USMLE World)
- “The average of my NBME self-assessments exactly predicted my actual score”
- I saw several questions that were similar to what showed up on my question banks and self-assessments. Studying the explanations was the essential piece
- “I had several questions that came straight from my question bank”
- “I didn’t recognize any of the questions from my exam. It could have been from Mars. None of the questions banks helped.” (Bear in mind that these students were very nervous coming out of the exam. However, in scoring they were compared with everyone else taking this same version of the exam and they always did quite well when their scores were returned. They had become good, knowledgeable test takers by completing question banks and thoroughly preparing, even though they did not feel familiar with the question format on their exam.)
Research indicates that there are moderate correlations between performance on the NBME self-assessments and Step 1 scores. It is suggested that a student take 2-3 assessments in a short period of time before their actual Step 1 exam and average those scores together to determine readiness for sitting for the USMLE. Taking this, along with the student’s average on their question bank (USMLE World or Kaplan) over that last 15-20, 45 to 50-question timed practice tests will tell a student if she is ready to take the leap to take the exam.
When to take the Self-Assessments?
We suggest that students take an easier NBME self-assessment at the very beginning of their study period to
- establish a baseline for comparison later progress
- make decisions about how long it will take to reach your Step 1 goals
- make decisions about board preparation plans and programs to useThe NBME Self-Assessment: You will receive a score on a scale of 800, with a mean of 500, but you will receive a profile and a score interpretation sheet which will translate your score into a 3-digit score. If your baseline 3- digit score is 155 or below, a student may want to consider taking additional time to prepare, as this is an indication that foundational work is required for passing the Step 1 exam.
To view a sample NBME self-assessment profile:
You can take self-assessments midway through your study plan period, especially if you are doing this to train yourself to take longer timed tests, attempting to simulate the stresses of the actual examination to practice anxiety management, or tracking your progress with actual NBME type questions. All of these are excellent reasons if you have the $50.00 to purchase the 4-hour exams every 4-5 weeks.
On a 12 to 20 week plan, a student should sit for two NBME self-assessments 4 and 6 weeks, respectively, prior to the end of their plan to make sure they are progressing as planned and will not need to add additional time to their study plan.
It would also be beneficial for a student to take 2-3 NBME self-assessments 2 weeks prior (14-15 days) to sitting for Step 1 for the same reasons. You should be taking the harder exams at this time and attempting to score 195 and above to assure you are not falling too far to the left of the standard deviation resulting in a failing score. If at all possible, a student should delay taking the exam rather than have a failure on their record.
If you purchase an NBME form with expanded feedback (the $60 version) you will receive additional information providing a breakdown of incorrect answers by content category. This includes the number of items you answered incorrectly, the average amount of time spent on each item, and the percentage of incorrect items you marked during your self-assessment. You can use this information to figure out your areas of weakness and the number of errors you made on a particular subject (the expanded versions used to come with explanations to the questions. Self-assessment #6 does not, and we are checking with the NBME to see if any of the other 2011 self-assessments are providing explanations). You can also formulate a study plan based on how long you spent on each question category.
You will see many suggestions on the Internet discouraging students from purchasing the NBME self-assessments. These assessments use PDF versions where you take the test and come up with a percentage correct, but conversions to predictive Step 1 scores may not reliable. Even if you are not converting the score, a percentage may not give you the information you need to make informed decisions.
However, it is understandable when funds are limited to do what you can to stretch your dollars as far as they will go. If this is the case, then limit your NBME self-assessments to those closer to the examination date. Make sure they start at least 2 weeks ahead of the examination date and that you take the more difficult self-assessments.
In addition, be sure to take more than one self-assessment. You cannot rely on just one to know if you are ready to take the exam. Be sure to take at least 2, if not 3, close together and average them to get a good idea of how you do under different conditions, with different exam questions, on different days.
Please leave comments on your experiences. It helps all of us to hear what is happening in this current, 2011 season.
NBME self-assessment website
For additional information about the NBME self-assessments (CBSSA)
To see a sample profile
It's important to have a strategy for what and when you will study. Many students find the structure of the Doctors In Training USMLE Step 1 Review Course beneficial to their exam preparations. Our course presents the high yield information you need to know and is updated annually to reflect student feedback.