How to succeed at MCQs

What is an MCQ exam?



Medical school examiners love multiple choice questions (MCQs), because they're great at testing your factual knowledge, objective (they're marked by a computer, so there's no chance of favouritism), don't suffer from variations in marking, and are quick and easy to mark - which is important when you have hundreds of students. However, MCQs can't be used to test practical skills, such as how you communicate with or examine patients - this is where the OSCE comes in, but that's a whole other topic.

If you've spent any time at all at medical school, you'll be familiar with the MCQ style of exam. If you're new to medical education, however, you might be wondering what all the fuss is about, in which case it's highly likely that you've never before sat an exam that can result in a negative score. Yes that's right, not just a low score, but a score in minus figures! Some medical schools use negative marking, and some don't - you need to find out whether your does. Back in the day, all medical schools used negative making, so it is perhaps little wonder that med students believe their degree courses to be more difficult than most.

Nowadays not all MCQ exams are negatively marked; if your medical school doesn't use negative marking, you are indeed fortunate, and you can skip the parts of the course that cover negatively marked MCQs. However, it's worth bearing in mind that most postgraduate exams are still negatively marked, so if you don't need the advice on coping with negative marking now, it will come in handy in the future.

If your exams are negatively marked, you'll be given one mark for a correct answer, no mark for an unanswered question, or a 'don't know', and you'll have one mark deducted for a wrong answer. Doesn't sound too bad, you're thinking, I'll just hedge my bets and leave anything I'm not sure of, but it's not that straightforward. Consider the following scenario:

You are answering an MCQ exam which has 100 questions. You answer 70 questions and leave the 30 you're not sure of. You can now only achieve a maximum score of 70%. However, you only get 80% of the 70 questions you answered correct. That gives you 56 out of 70, but with negative marking you loose one mark for every question you get wrong, so that's 14 marks deducted from your score of 56 - leaving you with a less-than-impressive 42.

What would have happened if you'd made an educated guess for the 30 questions you weren't sure about?

You decide to take a chance with the 30 tricky questions, and using a process of educated guessing, deduction and blind faith you answer all 30. Luck is with you and you get half the questions correct - that's 15 out of 30. However, with negative marking that gives you a net score of 0 for these 30 questions. Your overall score for the test is still 42.

You're no better off than before, but you're no worse off either, so is it worth having a go? Consider what would happen if you were very unlucky:

You decide to try to answer the 30 troublesome questions; however, you only manage to get 10 out of 30 correct. 20 incorrect answers gives you a score of -10. This -10 will be deducted from the 42 you scored for the remaining 70 questions, giving a net score of 32 - disaster!

Perhaps it's best to leave those 30 troublesome questions? But what if luck is on your side...

You decide to try to answer the 30 troublesome questions; you're having a good day, and manage to get 20 of them correct. This gives you a net score of 10. Now you have scored a not unrespectable 52.

Do you see how negative marking can complicate things?

"I'll never pass", you're thinking, but relax, with the right preparation and technique you'll pass with flying colours. Read on to find out how to prepare effectively for an MCQ exam, and how to hone your question answering technique.

MCQs: the basics

First we'll start with the basics: what does a typical MCQ look like? Take a look at the example below:

Ventricular fibrillation is a recognized hazard in

A. ventricular ectopics occurring on the peak of the R wave.
B. digitalis toxicity
C. overdrive pacing.
D. prolonged QT interval.
E. third degree (complete) heart block.

(correct answers: BDE)

The typical MCQ is made up of a 'stem' or statement followed by several (often five) related completion items or options. The statements following the stem can be all true, all false, or a combination of true and false (sadly, unlike the example above, the answer is never handily provided in brackets after the question). The incorrect answers are called 'distractors' - they are meant to distract you from the correct answers, and for this reason, the distractors will be close enough to the correct answers to be plausible.

The stem should be read in turn with each of the completion statements. Each statement is independent, and there will be no fixed pattern to the number of true or false answers.

You may also be given the option of answering true or false for each statement, and there may even be a don't know (DK) option. There's an example below:

The following are risk factors for breast cancer:

High alcohol intake T F DK
Nullparity T F DK
Late menopause T F DK
Early pregnancy T F DK
Late pregnancy >30yrs T F DK

The most common format currently used for MCQ exams is the extended matching item (EMI), or extended matching question (EMQ). An EMI question is similar to an MCQ in that you still have a stem and a range of options to choose from; however, EMI questions are thought to be a better tool for getting students to apply knowledge, as although more than one of the options might be correct, it's the best answer that's required. The question takes the form of a short case study that may include details such as test results, signs or symptoms. Students are then asked to make a diagnosis. Take a look at the example below, which is taken from Susan M. Case and David B. Swanson's Constructing Written Test Questions for the Basic and Clinical Sciences (Third edition, 2002).

An EMI question:

A. Acute leukaemia H. Hereditary spherocytosis
B. Anaemia of chronic disease I. Iron deficiency
C. Congestive heart failure J. Hyperthyroidism
D. Depression K. Lyme disease
E. Epstein-Barr virus infection L. Folate deficiency
F. Microangiopathic haemolytic anaemia M. Miliary tuberculosis
G. Glucose 6-phosphate dehydrogenase deficiency N. Vitamin B12 deficiency

For each patient with fatigue, select the most likely diagnosis

1. A 19 year old woman has had fatigue, fever, and sore throat for the past week. She has a temperature of 38.3C (110F), cervical lymphadenopathy, and splenomegaly. Initial laboratory studies show a leukocyte count of 5000/mm3 (80% lymphocytes, with many lymphocytes exhibiting atypical features). Serum aspartate aminotransferase (AST, GOT) activity is 200U/L. Serum bilirubin concentration and serum phosphatase activity are within normal limits.

(answer: E)

2. A 15 year old girl has a two-week history of fatigue and back pain. She has widespread bruising, pallor and tenderness over the vertebrae and both femurs. Complete blood count shows haemoglobin concentration of 7.0 g/dL, leukocyte count of 2000/mm3, and platelet count of 15,000/mm3.

(answer: A)

For the example above, you would need to choose the correct answer for each question from the list of options.

Activity: What will your MCQs or EMIs look like? - 10 minutes

It's important to know what kind of questions you'll get - and whether you'll be negatively marked, so you know what to practice, and what's the best question answering technique for you to adopt.

1. If you don't already know, find out what format your MCQ exams will take. Your study guide or course handbook is a good place to look, or, you could ask a friendly lecturer. Students in the years above you may also offer you some good advice.

Recommended Further Reading

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