Islands of knowledge or puddles of ignorance


How do examiners, or for that matter your referrers or colleagues, form an opinion of your competence? This may seem like a glib question, but stop and consider.

An examiners duty, at a fundamental level, is to decide if you know enough about everything relevant to the practice of radiology to be unleashed on an unsuspecting and largely trusting public. How do they try and accomplish this daunting task? Well, they show you a handful of cases. Statistically this is not a very sound method, after all, even if you consider knowledge in a very superficial way, there are thousands upon thousands of individual facts, and during an exam only a tiny fraction of this knowledge can be directly examined.

So what do they do? They judge you based on a few answers and extrapolate from there to the totality of your possible knowledge. If that worries you, it should, but only if your technique is lousy.

A candidate with good technique will convince the examiner that each correct answer represents merely an example of a vast amount of untested knowledge, whereas each incorrect answer is an unfortunate fluke,  just happening to land in a tiny puddle of ignorance.

Poor technique, on the other hand, will convince the examiner of the opposite. Each correct answer represents a chanced up inconsequential island of knowledge stranded in a vast ocean of ignorance. Each incorrect answer on the other hand, merely confirms how little that candidate knows.


Thus, with exactly the same mix of correct and incorrect answers, your technique can give very different impressions, and in many cases be the difference between passing and failing.

So where does that leave you? Time to pack it in and go home and cuddle up to a large tumbler of single malt on the couch while watching The Wire for the third time (this is a fairly good plan at the best of times; The Wire is after all the best TV ever made)? Well, perhaps, but not because of the unfairness of exams. There is a relatively simple solution; stop studying and start thinking and practicing. It is my day to day experience that trainees have absorbed great quantities of factual knowledge but have not taken the time to tie all of it together, and that as a result in an exam setting, or when speaking to clinicians, they come across far more ignorant than they actually are. Now you need to take the time to work out how all these facts and disparate conditions fit together in the context of cases, and be able to articulate this quickly and clearly in an oral setting.

I have already covered some aspects of how to effectively practice without wasting time and how to practice your oral technique in the shower in previous posts, and in future posts I hope to also go into how to use cases as the starting point for study, the secret art of relevant negatives and why you should never surprise your examiner, but for now if you are in sight of your exams, let me leave you with this advice: you are better off practicing cases until you are limited by your knowledge and not your technique. Then and only then, hit the books again. 


Next: The secret art of relevant negatives


Dr Frank Gaillard is a neuroradiologist at the Royal Melbourne Hospital, Melbourne, Australia, and is the Founder and Editor of

NB: Opinions expressed are those of the author alone, and are not those of his employer, or of


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Publication date: 2nd Apr 2014 01:54 UTC

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