NATIONAL BOARD OF MEDICAL EXAMINERS Examination Interpretation Guide NBME subject examinations provide medical schools with a tool for measuring examinees' understanding of the clinical sciences. Although these examinations are designed to be broadly appropriate as part of overall examinee assessment, course objectives vary across schools, and the congruence between subject examination content and course objectives should be considered when interpreting test scores and determining grading standards. Specifically, subject examination scores should not be used alone, but rather in conjunction with other indicators of examinee performance in determination of grades. Subject Examination s The subject examination score is scaled to a mean of 70 and a standard deviation of 8. A Comprehensive Clinical Science Examination () score of 70 is approximately equivalent to a score of 200 on the United States Medical Licensing Examination (USMLE ) Step 2 Clinical Knowledge (CK). The vast majority of scores range from 45 to 95, and although the scores have the "look and feel" of percent-correct scores, they are not. Because the and USMLE Step 2 CK cover very similar content, this scale provides a useful tool for comparing the scores of your examinees with those of a large, nationally representative group taking the licensing examination at the end of the second year of medical school. Additional information about the relationship between scores and USMLE Step 2 CK scores is provided in the table on the next page. Unlike percent-correct scores, subject examination scores are statistically equated across test administrations. s are statistically adjusted for shifts in test difficulty across different forms of the examination. This makes it possible to track school and examinee performance over time. Precision of s Measurement error is present on all tests, and the standard error of measurement (SEM) provides an index of the (im)precision of scores. The SEM indicates how far an examinee s score on the examination might stray from his/her true proficiency level across repeated testing using different sets of items covering the same content. Using the SEM, it is possible to calculate a score interval that will encompass about two thirds of the observed scores for a given true score by adding and subtracting the SEM from that score. For this examination, the SEM is approximately 4 points. For example, if an examinee s true proficiency on the examination is 60, the score he/she achieved on the examination will usually (two times out of three) fall between 56 and 64 (60-4 and 60 + 4). and Performance Feedback Summary information on the examinee group tested, examination purpose and number of items scored is provided on each page of the feedback. The Roster of Scaled s reports a total test scaled score for each examinee. Reported scores also appear in a comma separated text file that can be downloaded and used to export scores. If there were at least 2 examinees, Scaled Descriptive Statistics for reported scores are provided along with a Frequency Distribution of the total test scaled score. If there were at least 10 examinees, a Content Area Item Analysis Report is provided. If there were at least 15 examinees, a School Summary Performance Profile is provided. An Examinee Performance Profile, which graphically displays content areas of strength and weakness, is provided for each examinee. ccse_2011_1001
NATIONAL BOARD OF MEDICAL EXAMINERS Examination Approximate USMLE Performance Equivalents The table below provides approximate performance equivalents for USMLE Step 2 CK, making it possible for you to translate the scores of your examinees to the scale used for USMLE Step 2 CK. Specific information on USMLE Step 2 CK and the current minimum passing score is available on the USMLE web site at www.usmle.org. To use the table, locate an examinee s score in the associated column and note the entry in the column labeled "Step 2 CK Equivalent". For example, if an examinee s score is 60, the corresponding entry of 175 indicates that the examinee's performance on the is approximately equivalent to a Step 2 CK score of 175. Note: This examination is not intended to predict performance on USMLE. Rather, it is intended to be used to determine an examinee s relative areas of strength and weakness in general topic areas. Approximate Step 2 CK Equivalents Norms for Examinee Performance The table below provides norms to aid in the interpretation of examinee performance. The norms reflect the performance of a group comprised of 3,002 examinees from LCME-accredited medical schools who took the paper version of the for the first time during the 2008-09, 2009-10 and 2010-11 academic years (8/1/2008 7/31/11). This group had a mean of 70 and a standard deviation of 11 on the score scale. To use the table, locate a student s score in the associated column and note the entry in the column labeled "Percentile Rank". For example, if an examinee s score is 70, the corresponding percentile rank of indicates that % of the national group of examinees taking this examination had scores at or below 70. 2008-2011 Academic Years Norms Percentile Rank Percentile Rank 94 92 90 88 84 82 70 Step 2 CK Equivalent 260 255 250 245 240 235 230 225 220 215 210 205 200 64 62 60 56 54 52 50 48 46 44 Step 2 CK Equivalent 195 190 185 1 175 170 165 160 155 150 145 140 135 92 91 90 88 87 85 84 82 81 79 77 75 97 96 95 95 94 92 90 88 85 79 75 70 70 65 64 63 62 60 57 56 55 54 64 57 50 46 42 37 35 31 28 24 23 19 16 14 12 10 9 8 ccse_2011_1001
Scaled Descriptive Statistics Scaled score descriptive statistics (mean, standard deviation, lowest score, and highest score) for the examination administered on the specified test date(s) are listed below. Please refer to the Interpretation Guide for information about how to interpret the scores. Medical s MSS - 2009 # 01 # d Items 1 Category Description Test Mean.4 Standard Deviation 12.4 Low 44 High Page 1 of 5
Roster of Scaled s The roster of scores contains scaled score(s) for each examinee who tested on the specified test date(s). These same scores also appear in a comma separated value text file that can be downloaded and used to export scores into your local database. Please refer to the Interpretation Guide for information about how to interpret the scores. Medical s MSS - 2009 # 01 # d Items 1 ID 0046 0045 0044 0043 0042 0041 0040 0039 0038 0037 0036 0035 0034 0033 0032 0031 0030 0029 0028 0027 Name Page 2 of 5
Roster of Scaled s Medical s MSS - 2009 # 01 # d Items 1 ID 0026 0025 0024 0023 0022 0021 0020 0019 0018 0017 0016 0015 0014 0013 0012 0011 0010 009 008 Name 44 98 63 Page 3 of 5
Roster of Scaled s Medical s MSS - 2009 # 01 # d Items 1 ID 007 006 005 004 003 002 001 Name 87 Page 4 of 5
Scaled Frequency Distribution Medical s MSS - 2009 # 01 # d Items 1 Scaled 44 63 87 98 Cumulative Frequency Frequency Count % Count % 6 13 8 17 9 19 10 21 14 30 18 38 20 43 23 49 24 51 27 57 29 62 31 35 36 77 39 40 85 41 87 42 43 91 44 100 Page 5 of 5