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PLAB Part 2 borderline group scoring method - Frequently asked questions


  
  1. 1. How do the examiners mark the Part 2 exam using the borderline group scoring method?
  2. 2. Is each objective worth the same?
  3. 3. How do you work out my score for the station?
  4. 4. Is there a fixed pass mark for each station?
  5. 5. How do you work out the pass mark for each station?
  6. 6. What is a borderline performance?
  7. 7. How do I pass a station?
  8. 8. Does the examiner know the station pass mark?
  9. 9. How do you work out if candidates meet the required standard of the Part 2 exam?
  10. 10. If I meet the criteria, what will I be told?
  11. 11. If I do not meet the criteria, what will I be told?
  12. 12. What if my score exceeds the total score but I pass eight stations?
  13. 13. Is the borderline group scoring method a new way to standard set exams?
  14. 14. Why are you introducing it to the PLAB Part 2 exam?



1. How do examiners mark the Part 2 exam using the borderline group scoring method?

The examiners will mark each station based on your performance against the individual objectives in it (such as presenting complaint, approach to the patient etc). You will not see the objectives, but they will be on the examiner’s mark sheet. The examiner awards a grade between A and E for each objective.

2. Is each objective worth the same?

No, each objective is weighted. The total weightings for each station add up to 100%. Some objectives are worth more than others. The examiner is not aware of the weightings for the station, only the objectives.

3. How do you work out my score for the station?

After the exam, the grades awarded by the examiner in a station are converted to marks (A = 4, B = 3, C = 2, D = 1, E = 0). A score is calculated for each station by multiplying the mark given for each objective by the percentage allocated and then adding them up. So if you were awarded B, C, A, D for four objectives in a station which was weighted 40%, 30%, 20%, 10%, you would score 2.70.

3 x 0.40 = 1.20
2 x 0.30 = 0.60
4 x 0.20 = 0.80
1 x 0.10 = 0.10
Total = 2.70

4. Is there a fixed pass mark for each station?

No, using the borderline group scoring method, each station has a pass mark, which varies with the difficulty of the station.

5. How do you work out the pass mark for each station?

In addition to marking the individual objectives in your station, the examiner will also make an overall judgement as to whether your performance rates as pass, borderline or fail. These judgements do not influence whether you pass or fail the station. Only your score from the individual objectives will do that. The overall judgement is used to determine the pass mark for future candidates. We take the mean scores of previous candidates judged borderline in each station to work out the station pass mark.

6. What is a borderline performance?

A borderline performance is that of the minimally competent candidate. A minimally competent candidate is one whose performance the examiner considers safe and is generally satisfied with, but has some concerns about.

7. How do I pass a station?

To pass a station, your score must meet or exceed the station pass mark. If the score is below the station pass mark you will fail that station.

8. Does the examiner know the station pass mark?

No, the examiner does not know the weightings for the station nor the pass mark.

9. How do you work out if candidates meet the required standard of the Part 2 exam?

We add up the borderline scores for each of the 14 stations in the exam (pilot stations do not count towards your result). We then add one standard error of measurement. This creates the total score for the exam. Candidates must meet the required standard of TWO criteria. You must meet or exceed the total score for the exam and achieve the passing score in a minimum of nine stations. You must meet both criteria to be successful.

10. If I meet the criteria, what will I be told?

Your result will be published in GMC Online confirming that you have met the minimum required standard and are eligible to apply for registration. A letter will then be sent to the address you gave when you attended the exam.

11. If I do not meet the criteria, what will I be told?

You will be told the total score required in the exam, the score that you achieved and a pass or fail result in each of the stations. This information will be published in GMC Online and in a letter that will be sent to the address you gave when you attended the exam.

12. What if my score exceeds the total score but I pass eight stations?

You will not meet the required standard. The reason candidates have to meet both criteria is to ensure that they have demonstrated an acceptable level of performance across a range of stations. Candidates who score highly in some stations cannot use this to compensate for low performance in other stations.

13. Is the borderline group scoring method a new way to standard set exams?

No, it is an established method of standard setting for medical exams. It is used by other medical regulators, medical Royal Colleges and a number of UK medical schools.

14. Why has it been introduced to the PLAB Part 2 exam?

We already use the Angoff method of standard setting for the Part 1 exam. One of the recommendations of the last review of the PLAB test was that standard setting should be introduced for the Part 2 exam. The borderline group scoring method is regarded as the most appropriate method of standard setting for Objective Structured Clinical Exams. Before we could introduce it, we had to gather borderline scores and develop our IT systems to accommodate the change.