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Dr. J.A. Illingworth

Extended Matching Questions

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I am enthusiastic about computer-marked extended matching questions (EMQs). I think they are much fairer, more reliable, and much less work for staff and students than alternative examination styles. They can be used formatively, with student feedback, or summatively for final assessments. The examples on this page are not secure, being intended for formative use, but they could easily be made secure for assessment purposes. They have been implemented using standard HTML and Javascript, which means that they will run on any computer without requiring any proprietary software or the payment of a licence fee. No Leeds University staff have been made redundant to pay for this website.

contents

  1. anatomy self-assessment tests

  2. classic EMQ paper format

  3. narrative - hormonal regulation

  4. free text - bacterial chemotaxis

  5. check boxes - colonic functions

  6. quantitative - experimental design

  7. graphic input - metabolic pathways

  8. free format - clinical case studies

  9. conclusions - a possible way forwards

  10. references

We have been using EMQs in Leeds for medical teaching for the last ten years, so several of the following examples are drawn from the "Nutrition & Energy" course, and also from BIOC2120 which was designed around the same time. They seem equally suitable for other disciplines, and lend themselves to computer evaluations, using websites with HTML forms.

Example 1: anatomy self-assessment tests

We run a computer practical in ICU3 on basic cross sectional anatomy that medical students will need to interpret CT and MRI scans. These tests provide some practice drill. Click the drop-down menus for response options, then click the submit button when done. The feedback level is adjustable from (i) basic marks, (ii) identify the mistake, or (iii) provide the correct answer. [If you decide to change the feedback level, you must press the 'Submit' button again to re-run the test.] This question-setting technique will work with any graphic image: histology or species identification for example, electron micrographs, metabolic pathways, or molecular biology cartoons. Click here for some more tests - these were really easy to set up!

self-assessment test

Item

Identity

1. A

2. B

3. C

4. D

5. E

6. F

7. G

8. H


 

feedback: 

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Example 2: classic EMQ paper format

The classic EMQ format is built around a theme, which in the following example is the gene family "SLC25" whose protein products are plugged through the mitochondrial inner membrane. The logical necessity for this group of transport proteins was famously predicted by Peter Mitchell in the mid 1960's, several years before their existence was eventually demonstrated in the laboratory. For a recent report, please see Haitina, T et al (2006) Fourteen novel human members of mitochondrial solute carrier family 25 (SLC25) widely expressed in the central nervous system. Genomics 88(6), 779-790.

The theme is introduced by a lead-in which is followed a list of up to twelve options:

For each of the processes listed below, select the mitochondrial inner membrane carrier system which is most likely to be involved. Each option may be used once, more than once, or not all.

options

The options are followed by up to five questions that all share the same option list.

processes

1. Apoptosis: a component in the permeability transition pore.

2. Oxidation of cytosolic NADH: an electroneutral carrier.

3. Fat biosynthesis from carbohydrate: an essential carrier.

4. Oxidation of long-chain fatty acids: an essential carrier.


 

feedback:  please remember to re-submit if you change the feedback setting

Distractors are the plausible but incorrect statements included as alternative choices in a traditional MCQ. It can be difficult to choose good distractors, and for formative tests students sometimes remember the best distractors in preference to the correct answer! For EMQs the valid answers to the other questions in the same set usually make excellent distractors. EMQs need not contain ANY false statements and are much more difficult to guess.

It is sometimes claimed that EMQs are more difficult to compose than MCQs, although good MCQs can be very difficult to write. This seems to be more a question of familiarity than inherent difficulty, because it has not proved difficult to generate a wide variety of formative EMQs for medical teaching, or for the BIOC2120 course.

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Example 3: narrative - hormonal regulation of metabolism.

Paper versions of EMQs normally share the same set of options, and this may be an advantage where there is stong linking theme. There is, however, no need for this restriction when the questions are completed on screen. For convenience, the next set of questions are gathered together at the end, but they could easily have been dispersed through the text. The following "urban myth" explores a range of physiological adjustments. The options vary from one question to the next.

An urban myth:

A young woman lies asleep dreaming of a holiday abroad. Her bed is warm and comfortable but she stirs slightly in the small hours as the sky begins to lighten and her stomach reminds her that it is almost time for breakfast.

Suddenly she awakes and looks at the clock. "Oh ****!" she says, and leaps from the bed, frantically pulling on her clothes. Skipping breakfast and her morning shower she races from the house and sprints for the bus stop at the far end of her street. She makes the bus with seconds to spare and collapses on a seat to regain her breath.

By the time she gets to work about 30 minutes later she has almost recovered her composure. She puts her head round the bosses door: "I missed breakfast, but have I time to do my hair before the interview?"

"It's okay" says the bosses secretary "he's rung in sick. You can get your breakfast in the staff canteen."

By this stage she is really hungry, and orders poached eggs on toast with sausages and baked beans, washed down with a big mug of coffee, and some more toast and marmalade. As she settles down to read the newspaper, she realises that she needs to visit the loo...

If you have a pop-up blocker running, please switch it off. Mouse over the "hint" buttons for extra help.

 questionsanswersnotes

Which pituitary hormone was released in waves as she dreamed of her holiday?

This acted mainly on her liver, which released a second polypeptide hormone in response.

Which hormone was released in larger quantities as dawn was breaking?

You should know where this hormone comes from and what it can do.

Which hormone was released into her blood as she sprinted for the bus?

You should know where this hormone comes from and what it can do.

Which group of voluntary muscle fibres were recruited for her sprint?

These fibres are rarely used.

Which peptide hormone helped mantain her blood sugar, recovering on the bus?

She was hungry and stressed by the impending interview.

Which hormone was being released as she put the lid back on the marmalade?

She was warm, relaxed and full of food.

Which hormone helped to terminate her breakfast?

Several other hormones will help to delay the start of her next meal.


 

feedback:  please remember to re-submit if you change the feedback setting

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Example 4: free text - bacterial chemotaxis

This is based on the article by Wadhams & Armitage (2004) Nature Reviews Molecular Cell Biology 5, 1024-1037. This somewhat prolix example is a little repetitious and intended for formative use. It describes the functions of the enzymes and asks the students which is which, but it is equally possible to name the enzymes and ask instead what they do. A summative version could be much shorter than this example.

Reprinted by permission from Macmillan Publishers Ltd: Wadhams GH & Armitage JP (2004) "Making sense of it all: bacterial chemotaxis" Nature Reviews Molecular Cell Biology 5, 1024-1037, fig. 2 copyright 2004. License number 2327540163221

Eukaryotic sensory pathways commonly rely on serine, threonine or tyrosine protein kinases, whereas prokaryotes often use histidine–aspartate phosphorelay (HAP) systems. HAP systems have at least two components — a dimeric histidine protein kinase (HPK) and one or more response regulators (RR).

CheA is a dimeric HPK that interacts with transmembrane receptors. The kinase domain of one monomer phosphorylates a residue in the other. The phosphoryl group is then transferred to a conserved residue of the relevant RR, activating the output domain of the RR. Two response regulators CheY and CheB compete for binding to CheA.

E. coli move by rotating five to eight helical flagella anticlockwise, causing them to wrap together into a bundle that propels the cell forwards. Temporarily rotating some flagellae clockwise disrupts this bundle, causing the cell to tumble. When the motors resume anticlockwise rotation, the cell has reorientated and swims off in a new direction. In homogeneous environments, bacteria producing random motion. In non-homogeneous environments, variations in the intervals between tumbling bias the overall motion towards regions containing higher attractant concentrations, or lower concentrations of toxic chemicals.

Bacteria are too to sense a spatial concentration gradient along their length and therefore use temporal sensing to monitor the concentration at more widely separated points.

E. coli can detect transient changes in ligand concentration despite long-term variations in background concentration spanning five orders of magnitude. Chemotactic signals are detected by four dedicated transmembrane chemoreceptors: Tsr, Tar, Trg and Tap. These methyl-accepting chemotaxis proteins (MCPs) protrude through the inner membrane into the periplasmic space. MCPs bind some ligands directly, but respond to others with the assistance of periplasmic binding proteins. An adaptor protein, helps to link the MCPs to the cytoplasmic HPK, CheA.

A continuously active methyltransferase enzyme preferentially methylates those MCPs which have bound attractants, but ignores those which have bound repellants. removes these methyl groups. This ultimately causes the average methylation level to track the net attractant / repellant balance, after a slight delay.

Decreased concentrations of attractants result in decreased occupancy of MCPs, which stimulates CheA trans-autophosphorylation. This increases the concentration of which binds to the flagellar motor, causing a switch to clockwise rotation. This results in cell tumbling and direction change. A phosphatase terminates this process.

CheB is also phosphorylated by and results in an increased methylesterase activity and demethylation of the MCPs. Demethylated MCPs have a reduced ability to induce CheA autophosphorylation (even in the presence of a low concentration of attractant) so the rate of CheA autophosphorylation and therefore the rate of direction changing returns to the pre-stimulus level. Adaptation is complete and the system is ready to sense further changes in ligand binding.

Increased concentrations of attractant inhibit the autophosphorylation of CheA, which reduces the concentration of and therefore reduces the frequency of motor switching. This causes bacteria to swim for longer in the current desirable direction. CheB phosphorylation and methylesterase activity is also reduced, allowing to re-methylate the MCPs. Methylated MCPs stimulate CheA autophosphorylation, even in the continued presence of a chemoattractant, so CheA autophosphorylation returns to the pre-stimulus level and the bacterium to a normal frequency of direction changing.

The MCP signalling domain contains two adaptation regions, each with four to six glutamate residues that can be reversibly methylated. Some of these glutamates are actually encoded as glutamines, which mimic methylated glutamates and probably ensure that newly translated MCPs are inserted into the membrane in a neutral signalling state. CheB is a dual-function enzyme, which can deamidate as well as demethylate MCPs. Deamidation of the glutamine residues to glutamates exposes new targets for methylation by CheR and, therefore, for adaptation.


 

feedback:  please remember to re-submit if you change the feedback setting

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Example 5: check boxes and radio buttons

Drop-down option lists may be unsuitable where each option involves long textual strings, or when more than one answer might be correct. Fortunately, these very common situations are readily handled by the use of "radio buttons" for single options, and check boxes, where any number of options might be correct.

Functions of the colon

A. Which of the following arteries supply the large bowel with blood?

coeliac trunk 1

common iliac 2

hepatic 3

ileocolic 4

left gastroepiploic 5

inferior mesenteric 6

right gastroepiploic 7

short gastric 8

splenic 9

superior mesenteric 10


    feedback options:

B. Which of the following substances are normally absorbed in the large intestine?

amino acids 1

bile salts 2

butyrate 3

chloride 4

glucose 5

iron 6

sodium 7

triglycerides 8

vitamin B12 9

water 10


    feedback options:

Drop-down lists, such as the example below, could if necessary exploit the "set multiple" option available on HTML forms. Users must then hold down the ctrl key to make multiple selections. In most cases check boxes are an easier solution. In the present example only one option is allowed.

C. Identify the features on the section of colon.

A

B

C

D

E

F

G

H

I







HTML forms also allow free text input from the user, but it is a real challenge to correctly parse and interpret such text. Except for numeric input, or very simple words and phrases, linguistic analysis still requires a human examiner!

Thumbwheel controls are another way to get numbers from the user. They look good, although it is difficult to see what real advantages they offer over ordinary Javascript, which can readily parse numeric input text. For formative use, it is easy to make the question form check whether or not the user input lies within some pre-defined range, and to generate appropriate remedial text if a student has made a mistake in their calculations. For summative use the form might simply check for obvious typing errors before confirming that the user input had been accepted. Buttons and thumbwheel controls could also be used to imitate instrument control panels.

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Example 6: experimental design

Computer-marked extended matching questions lend themselves to tests of experimental design, in ways that would be more difficult to achieve with conventional paper MCQs. The following example tests basic skills with weighing, dilutions, extinction coefficients and the Henderson-Hasselbach equation. It is based on enzyme assays, but many other laboratory protocols lend themselves to this approach.

Metabolite measurements

It is desired to measure the concentrations of pyruvate, ADP and creatine in deproteinised tissue extracts, using coupled enzyme assays. All three compounds can be individually determined at pH 7.3 by measuring the oxidation of NADH using a spectrophotometer. Good quality supplies of potassium dihydrogen orthophosphate, disodium hydrogen orthophosphate dihydrate, magnesium sulphate heptahydrate, phosphoenolpyruvate, NADH, lactate dehydrogenase, pyruvate kinase and creatine kinase are provided.

The assays will performed in a final total volume of 1ml, the relative volumes of neutralised tissue extract and diluent (water) being adjusted to achieve an overall decrease in absorption of approximately 0.5 during the experiment, using 1cm path length cuvettes. In total, nine additions must be made to each cuvette, although in practice some of these might sensibly be combined into a cocktail to reduce the number of pipetting operations. In alphabetical order, these additions are: buffer, creatine kinase, diluent, lactate dehydrogenase, magnesium sulphate, NADH, phosphoenolpyruvate, pyruvate kinase and tissue extract.

The following reagents are listed alphabetically, and you are asked below to decide their most sensible order of addition to the cuvette. Small errors in weighing out the stock solutions are not critical - the accuracy of this method hinges on the enzyme specificity and the known extinction coefficient of NADH.

[We could, alternatively, ask our students to prepare an error analysis of this procedure - other than the ubiquitous "human error" which they love to invoke, they are likely to focus on weighing, pipetting, temperature, pH ... Actually, within reason, and for this particular protocol, many of these conventional factors have minimal effects on the overall results. The biggest sources of error are the sample preparation, and spectrophotometer drift.]

The enzymes creatine kinase, lactate dehydrogenase and pyruvate kinase are all available as pure, concentrated solutions and 5µl aliquots are added in an appropriate sequence to each cuvette. These small volumes can be ignored in subsequent calculations. The overall equilibrium constant for this sequence of enzyme reactions favours the oxidation of NADH. You may assume that under the conditions of this experiment, all of these reactions proceed to practical completion in a convenient period of time. The time course for your assays should look like this:

Magnesium sulphate should be prepared as a concentrated solution, and 50µl of this stock solution added to each spectrophotometer cuvette to achieve a final concentration of ~2mM. What quantity of MgSO4.7H2O (formula weight = 246) should be dissoved in 5ml water to prepare this concentrated stock solution?

NADH should be prepared as a concentrated solution, and 50µl of this stock solution added to each spectrophotometer cuvette. The millimolar extinction coefficient of NADH is 6.22 at 340nm wavelength. What quantity of NADH (formula weight = 742) should be dissolved in 5ml water to prepare this concentrated stock solution, such that the expected changes in absorption can be readily measured?

Phosphate buffer should be prepared as a concentrated solution, and 0.1ml stock added to each spectrophotometer cuvette. The relevant pK of phosphoric acid is 6.8 and the final phosphate concentration should be ~40mM. What quantities of Na2HPO4.2H2O (formula weight = 178) and KH2PO4 (formula weight = 136) should be dissolved in 20ml water to prepare this concentrated buffer solution?

Phosphoenolpyruvate, monopotassium salt [PEP] should be prepared as a concentrated solution, and 50µl of this stock solution added to each spectrophotometer cuvette. PEP is a "high-energy" phosphate donor, which helps to drive this assay in the desired direction. It is important to add sufficient, so that it does not run out, or become significantly depleted during the assay. On the other hand, it is probably contaminated with small amounts of pyruvate, so it would be a mistake to add too much. What quantity of PEP (formula weight = 206) should be dissoved in 5ml water to prepare a suitably concentrated stock solution, such that the expected changes in absorption can be readily measured?

What approximate weight of each reagent is required?

 

reagent

f.w.

quantity

dilution

1

MgSO4.7H2O

246

in 5ml stock; 50µl added to each 1 ml cuvette

2

NADH

742

in 5ml stock; 50µl added to each 1 ml cuvette

3

KH2PO4

136

in 20ml stock; 100µl added to each 1 ml cuvette

4

Na2HPO4.2H2O

178

in 20ml stock; 100µl added to each 1 ml cuvette

5

PEP

206

in 5ml stock; 50µl added to each 1 ml cuvette


 

feedback: 

It is not essential to add the first five reagents to the cuvette in any particular order. In what sequence must the remaining four reagents be mixed into the cuvette, in order to determine the metabolite concentrations in the tissue extract as accurately and completely as possible?

In what order should the various solutions be added?

sequence

addition

measures

sixth addition

1

2

seventh addition

3

4

eighth addition

5

6

final addition

7

8


 

feedback: 

Here are my own calculations, used to set up this problem:

MgSO4 final concentration 2mM, stock solution 40mM requires 0.04 moles/litre or 0.04 * 0.005 * 246.47 g/5ml = 49.2 mg/5ml

NADH in cuvette should be ~0.15mM (initial optical density ~0.9) stock solution is 3mM or 0.003 * 0.005 * 741.62 g/5ml = 11 mg/5ml

PEP in cuvette should be ~0.5mM (a 5-fold excess) stock solution 10mM requires 0.01 * 0.005 * 206.13 g/5ml = 10.3 mg/5ml There should be an excess of PEP over the NADH, but not too much because contaminating pyruvate will raise the blank readings.

Total phosphate in cuvette = 40mM, pH is 0.5 units above pK, so from Henderson-Hasselbach equation dibasic : monobasic = 3:1 approximately, so
KH2PO4 = 10mM and Na2HP04 = 30mM, therefore the stock solution should be 100mM KH2PO4 + 300mM Na2HP04

100mM KH2PO4 stock requires 0.1 * 0.02 * 136.09 g/20ml = 272 mg/20ml

300mM Na2HP04 stock requires 0.3 * 0.02 * 177.99 g/20ml = 1068 mg/20ml

Optimal order of additions is (1) sample, (2) diluent, (3) buffer, (4) MgSO4, (5) PEP, (6) NADH, (7) LDH, (8) PK, (9) CK
to minimise the risk of precipitation or denaturation and to measure the three unknowns in the correct sequence.

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Example 7: graphic input - metabolic pathways

Previous examples used labels to mark key features on diagrams. Sometimes labels might be undesirable, but it is also possible to exploit client-side image maps, which allow users to identify features for themselves.

The demonstration that follows asks students to identify various elements within the Krebs cycle and its associated reactions. It is readily extensible to any other graphic image, or even to an image bank. In addition to asking students to find items that they ought to recognise, we could also ask for value judgments: identify the most important features on a diagram, or mark any features that should be ignored.

Click the button below to start the test, then click in the diagram on the left to answer the questions

   

Questions auto-increment if answered correctly

In addition to images defined by spatial coordinates, we should also remember those defined by time. We could ask, for example, which frames within a video sequence illustrate particular effects, or which parts of a graph provide evidence for particular beliefs.

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Example 8: free format - clinical case studies

The preceding examples may be mixed freely in questions that imitate real life situations. These questions include value judgments about the relative importance that should be assigned to particular pieces of evidence. The same principles could be applied to the evaluation of scientific evidence.

Case one

Bill W. consulted his GP at his surgery on returning from a business trip abroad: "I've had the terrible runs, doctor. I don't feel that I can move out of sight of the toilet. Do you think I've got cholera?" He explained that his problems had started on the flight home: "We were in the hotel most of the week checking contract drawings, but on the last night we all went out for a meal in down town Beirut..." The interview was interrupted by an urgent visit to the lavatory. His GP handed him a specimen container.

Bill was 38 years old, slightly overweight, temperature 38°C, BP 150/90. His faecal specimen was fluid but otherwise normal appearance, and free from blood or mucus. He said that he had vomited twice on the plane, but not subsequently, and was passing urine normally.

A. Why would the GP consider that cholera was unlikely, although not impossible?

potential diagnostic informationclinical significance

1. Bill is too clear-headed for cholera.

2. Bill was vaccinated against cholera (only 50% effective) three years ago.

3. Blood pressure is 150/90, therefore he is not seriously dehydrated.

4. Cholera is currently rare in the Lebanon.

5. Cholera is declining world-wide.

6. Cholera is more serious in children.

7. Faeces are fluid but relatively normal.

8. Insufficient incubation period for cholera.

9. Low fever probably means a mild infection.

10. Nobody else in Bill's party has any symptoms (yet!)

11. Urine flow is OK, therefore he is not seriously dehydrated.


    feedback options:

The GP advised him to rest quietly at home, to keep warm and to drink plenty of fluids. He recommended a non-prescription medication containing NaCl, KCl and glucose to be taken in water after every bowel motion. "Take care with your personal hygiene: we don't want you infecting the rest of the family. There is no need to eat unless you feel hungry, but food won't do you any harm. I'll sign a sick note for your employer. Make another appointment if it gets any worse, or if it hasn't cleared up in three or four days."

B. Why did the GP not prescribe an immediate course of antibiotics?

clinical reasoning relative weight

1. Antibiotics would be too expensive.

2. This could easily be a viral infection.

3. This might be a protozoal infection.

4. Bill is likely to recover quickly without treatment.

5. Over-prescribing favours antibiotic resistant strains.

6. This patient is not very seriously ill.


    feedback options:

The glucose in the life-saving recipe below could advantageously be replaced by boiled rice flour in countries where this is more readily available, and the bicarbonate by any organic anion (such as acetate, lactate or citrate) that is metabolised to yield bicarbonate / CO2 in the body.

C. What were the purposes of the ingredients in the non-prescription product?

Purpose Ingredients

(check ALL boxes that apply: there could
be more than one correct answer per line)

NaCl
100mM

KCl
13mM

NaHCO3
50mM

glucose
110mM

water

To supply energy

1

2

3

4

5

To promote cation uptake

6

7

8

9

10

To prevent dehydration

11

12

13

14

15

To prevent metabolic acidosis

16

17

18

19

20

To maintain plasma osmolarity

21

22

23

24

25

To maintain cardiac rhythm

26

27

28

29

30


    feedback options:

"I can't possibly do that, doctor. We're about to sign the contract. I absolutely must be London tomorrow to meet this Lebanese group and clinch the deal. My job depends on it."

"In that case, you could try Imodium. Don't take it for any longer than is strictly necessary, and give the practice a ring if your symptoms get any worse."

D. The active ingredient in Imodium is loperamide.

Questions Answers

1. What type of drug is loperamide?

2. Why is loperamide preferred over other drugs in this class?

3. What effects does this class of drugs have on the gut?

4. When are these unwanted side-effects of other treatment?


    feedback options:


Case two

Lorna D. was a medical social worker who consulted her GP about chronic diarrhoea. "It's all day, every day, doctor. It's such a problem visiting clients. I just don't know how I am going to cope." She said she tried to eat a balanced diet, and couldn't think of any foods that seemed to upset her. A stool culture showed nothing unusual. Her motions were negative for occult blood.

Lorna was admitted to hospital for further tests. She passed 950ml of faeces over a 24-hour period. While conducting a colonoscopy examination the consultant noted the situation shown in image 2.

She questioned Lorna very closely about her eating habits before referring her to a psychiatric colleague for further advice.

QuestionsAnswers

1. What had the consultant seen?

2. What did she suspect might be going on?


    feedback options:


Case three

Michael E. was a 59 year-old Glaswegian bricklayer who developed a sudden pain in his left iliac fossa. On examination his temperature was 38°C, BP 160/95. He was overweight, but had previously been in good health apart from chronic constipation. "I feel like I need a crap right now, doctor, but I can't do anything."

A. 

  

QuestionAnswer

What is a the medical term for this sensation?


    feedback options:

His rectum was empty, but tender mass could be felt in the affected region. When asked about his diet, he described himself as "a real steak and eggs man" who didn't like vegetables...

His immediate problem resolved spontaneously, but the consultant decided to perform a more detailed colonoscopic examination because Michael's motions contained some visible blood. He noted, and removed, the structure shown in image 3 (above). Further colonoscopic examination revealed the situation shown in image 4 (left).

B. 

  

QuestionsAnswers

1. What is shown in image 3?

2. Why was it removed?

3. What is shown in image 4?

4. How is the patient's lifestyle
contributing to his problem?


    feedback options:

This condition can also be diagnosed from X-ray pictures taken after a barium enema:

Image 5

C. Consider the merits of colonoscopy versus X-rays with barium enema.
The following arguments have been advanced in relation to one or other of these procedures:

Arguments Colonoscopy X-rays with barium enema

Advantages

Disadvantages

Advantages

Disadvantages

biopsies and polypectomy are possible

1

2

3

4

direct vision

5

6

7

8

easier for the patient (allegedly!)

9

10

11

12

natural colour

13

14

15

16

radiation dose to patient

17

18

19

20

slight risk of bowel perforation

21

22

23

24

unpleasant for the patient

25

26

27

28

useful for changes in bowel habit

29

30

31

32


Check all the boxes where the above statements apply.

    feedback options:

Development of several bowel diseases has been associated with diets low in resistant polysaccharides or "dietary fibre". The differences between these polysaccharides may be tiny: starch (easily digested) and cellulose (completely resistant) differ only in the orientation of one chemical bond.

Some resistant polysaccharides are not digested at all, but some can be slowly fermented by bacteria in the lower gut. What are the major products of such fermentation? What are the obvious physiological effects?


Case four

Angela F. had suffered for many years from cramping, lower abdominal pain, associated with bloody diarrhoea. She was underweight, slightly anaemic, and sometimes also suffered from arthritis in her spine, hips and knees. Colonoscopy revealed the situation shown below but other areas of her colon were apparently normal. A biopsy showed that the disease involved the full thickness of her intestinal wall.


 diseased


 normal

The severity of her condition varied over time, and on this occasion forced her to seek a hospital appointment.

"Its getting bad again, doctor, and as usual I have these painful mouth ulcers as well."

A. Angela is suffering from inflammatory bowel disease [IBD]. It is often possible to distinguish between two variants: Crohn's disease and ulcerative colitis, although it is sometimes very difficult to decide between them. Which of the following symptoms are particularly associated with each variant, and which of them are common to all forms of IBD?

symptom Crohn's disease Ulcerative colitis

aphthous ulcers

1

2

arthritis

3

4

continuous areas of inflammation

5

6

crypt abscesses, loss of goblet cells

7

8

granuloma formation

9

10

involves the full thickness of the gut wall

11

12

occurs anywhere in the GI tract

13

14

only affects the colon

15

16

only affects the mucosa

17

18

patchy "cobblestone" appearance

19

20


Check all the boxes where the above symptoms are observed.

    feedback options:

Her consultant prescribed prednisone for 14 days, gradually tapering the dose to zero over several weeks. Angela had previously been treated with mesalazine, but in view of her relapse on this agent, her consultant decided to continue treatment with 6-mercaptopurine.

Why was the consultant reluctant to use prednisone indefinitely? [Look up the side effects.]

B. Which benefits and which side effects are seen with each drug? (Point at the drug names below for more information)

benefits and side effects prednisone mesalazine mercaptopurine infliximab

recommended for small bowel Crohn's disease

1

2

3

4

recommended for ulcerative colitis

5

6

7

8

bone marrow depression

9

10

11

12

central obesity

13

14

15

16

easy bruising

17

18

19

20

hyperglycaemia and diabetes

21

22

23

24

hypertension

25

26

27

28

infection

29

30

31

32

muscle wasting

33

34

35

36

nausea and vomiting

37

38

39

40

osteoporosis

41

42

43

44

thin skin

45

46

47

48


    feedback options:

This disease follows a highly variable course, but in severe cases may involve strictures, fistulae, peri-anal fissures and abscess formation. Eventually Angela may require surgery, but the smallest possible length of bowel would be removed because the recurrence rate is high.

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Conclusions and a possible way forwards.

Educational research over many years has demonstrated numerous advantages for the extended matching technique. The example questions on this website show that the archetypal EMQ design based on five questions with twelve alternatives can be extended and adapted into a wide variety of free-format versions. Where the EMQ questions are answered on screen it is particularly easy to incorporate multimedia techniques, and provide personalised feedback to the students in real time. We can readily accommodate graphic input and output, we can manipulate 3D protein structures on screen, and the extension to sound and video materials is easily achieved. All the examples on this website have been implemented using international standard HTML forms and Javascript functions, that are available free of charge throughout the world.

This is hardly a new technique. Staff involved in medical teaching have been using it for at least ten years, and it is nearly seven years since the late Professor Ed Wood's article in "Bioscience Education". All this begs that question of why we are still subjecting the majority of our life science students to hand-written examinations, which often fail to reveal their full potential, provide little or no feedback, have considerable hidden costs, and require many hours of staff time to mark. Instead of laboriously deciphering poor handwriting and hurried, clumsy diagrams, EMQ tests could be computer-marked in milliseconds, with total certainty about right and wrong. The marginal construction costs for additional EMQs are comparable with those of written questions plus marking schemes, while the assessment costs for computer-marking are very small. For accuracy, objectivity, reproducibility and audit there really is no contest.

We should still test students' literature searching, diagram drawing and scientific writing skills, but these are more appropriately measured by long essays or project work, where we expect much higher production standards, and everybody has time to think.

The present version of this website uses "client side" scripting and is not secure because the examples were always intended for formative work. It would be fairly easy to make it sufficiently secure for summative exams. If these were held in University computer clusters under exam conditions, then we could (1) move to "server-side" scripting with ASP or PHP, (2) only open the server for the duration of the exam, (3) switch to https:// (which encrypts the data) rather than http:// and (4) verify the username, password and IP address of each terminal. It would be difficult for anybody to defeat this in the limited time available, especially since we could also physically check that the correct student was sitting at the appropriate terminal.

Should we use a commercial package such as "Questionmark Perception" or material that we write ourselves? There are arguments in both directions:

My own view is that it is too early to decide which package to deploy, and the issues may look very different in three years time. It is, however, important that our Faculty begins to move away from traditional paper-based examinations, and starts to use more innovative techniques, initially for formative work. In a few years time people will have the knowledge and experience to make a more informed choice about the summative assessments.

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References

Some of these links use 'Informa' or 'OVID' to refer to publishers' websites. Such links are notoriously slow and unreliable, and will probably fail at some time in the future. Unfortunately these are the only links the library has on offer. All the paper references are valid, and if necessary users could generate new temporary links to the electronic versions using Google or Web of Science.

1. Bhakta, B et al (2005) Using item response theory to explore the psychometric properties of extended matching questions examination in undergraduate medical education. BMC Medical Education 5:9

2. Case, SM & Swanson, DB (1993) Extended-matching items: A practical alternative to free-response questions. Teaching and Learning in Medicine 5(2), 107 - 115. [via Informa]

3. Case, SM & Swanson, DB (2002) Constructing Written Test Questions for the Basic and Clinical Sciences. National Board of Medical Examiners.

4. Fenderson, BA et al (1997) The Virtues of Extended Matching and Uncued Tests as Alternatives to Multiple Choice Questions. Human Pathology 28, 526 - 532.

5. McCoubrie, P (2004) Improving the fairness of multiple-choice questions: a literature review. Medical Teacher 26(8), 709–712. [via Informa]

6. Swanson DB et al (2008) Measurement Characteristics of Content-Parallel Single-Best-Answer and Extended-Matching Questions in Relation to Number and Source of Options. Academic Medicine 83(10), S21-S24. ['Orrid OVID]

7. Wood, EJ (2003) What are Extended Matching Sets Questions? Bioscience Education 1-2

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I should be delighted to receive feedback on this website, and suggestions for how it might be improved. Email j.a.illingworth@leeds.ac.uk