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False knowledge and ignorance
VIEWPOINT
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Quinn TC, Wawer MJ, Sewankambo N, et al. Viral load and heterosexual transmission of human immunodeficiency virus type. N Engl J Med 2000; 342: 921–29. 6 Horton R. African AIDS beyond Mbeki: tripping into anarchy. Lancet 2000; 356: 1541–42. 7 WHO. WHO Tuberculosis Programme. Framework for effective tuberculosis control. Geneva: WHO, 1994 (WHO/TB/94.179). 8 Maher D, Chaulet P, Spinaci S, Harries AD. Treatment of tuberculosis: guidelines for national programmes, 2nd edn. Geneva: WHO, 1997 (WHO/TB/97.220). 9 Raviglione MC, Dye C, Schmidt S, Kochi A, for the WHO Global Surveillance and Monitoring Project. Assessment of worldwide tuberculosis control. Lancet 1997; 350: 624–29. 10 WHO. Global Tuberculosis Control WHO Report 2000. Communicable Diseases. Geneva: WHO, 2000 (WHO/CDS/TB/2000.275). 11 Mukadi YD, Maher D, Harries A. Tuberculosis case fatality rates in high HIV prevalence populations in sub-Saharan Africa. AIDS 2001; 15: 143–52.
12 Volmink J, Matchaba P, Garner P. Directly observed therapy and treatment adherence. Lancet 2000; 355: 1345–50. 13 Harries AD, Maher D. TB/HIV A clinical manual. Geneva: WHO, 1996 (WHO/TB/96.200). 14 Pozniak AL, Miller R, Ormerod LP. The treatment of tuberculosis in HIV-infected persons. AIDS 1999; 13: 435–45. 15 WHO. World Health Organization initiative on HIV/AIDS and sexually transmitted infections: safe and effective use of antiretroviral treatments in adults with particular reference to resource limited settings. Geneva: WHO, 2001 (WHO/HIS/2000.04). 16 Carr A, Cooper DA. Adverse effects of antiretroviral therapy. Lancet 2000; 356: 1423–30. 17 Bosman MCJ. Health sector reform and tuberculosis control: the case of Zambia. Int J Tuberc Lung Dis 2000; 4: 606–14. 18 Attaran A, Sachs J. Defining and refining international donor support for combating the AIDS pandemic. Lancet 2001: 357: 57–61. 19 Wood E, Braitstein P, Montaner JSG, et al. Extent to which low-level use of antiretroviral treatment could curb the AIDS epidemic in subSaharan Africa. Lancet 2000; 355: 2095–100.
Uses of error: False knowledge and ignorance I first became aware of error in the knowledge of students many years ago when I was teaching paediatrics in the University of Malaya. For example, when students were asked about the investigations needed to diagnose and manage a child with asthma, they would list everything from chest radiograph to serum folate. By listing everything they must include the correct answers and thus could not fail, even though some of the items listed were false, unnecessary, and perhaps dangerous. Examinations were marked as students expected, thus reinforcing their preconceptions. Traditional multiple choice questions (MCQs) expose the problem of false knowledge and error, but multiple true-false questions (MTFQs) reveal its extent. In these questions each part must be answered. With traditional scoring a student gets +1 for or a correct answer and 0 for omitting the answer or giving a wrong answer. The intelligent student has everything to gain and nothing to lose by guessing. This reinforced the message that correct answers passed exams, but wrong answers were irrelevant. Over the protests of the students and many teachers, I introduced MTFQs marked +1 for a correct response, –1 for wrong response and 0 for “I don't know.” I emphasised that saying, “I don't know”, was a definite statement about personal knowledge, so leaving an answer blank earned a score of –1. These questions showed that all students had some false knowledge. Interestingly, students had more difficulty in recognising that false statements were false, than in recognising true statements as true. I thought that these findings might be due to the alleged Asian proclivity for rote learning rather than understanding underlying principles. However, work in other countries has shown the same problems, with all students making some wrong responses but some students never admitting ignorance. A way of emphasising the danger of false knowledge and error is to incorporate penalties into examinations. Penalties for demonstrating false knowledge or error should make students critical of the knowledge they acquire and use. However, some teachers object to deducting marks and perhaps failing students on basis of error. It is also difficult to have all teachers agree on what is correct. When setting questions for examinations, we have had vehement disagreements even on anatomical structures, and the number of opinions about information needed for a firm diagnosis or the best management of a particular disease often equals the number of people discussing the matter. In the past teachers set papers or did clinical examinations without criticism from their peers, so these problems passed largely unnoticed. Peer review of written examination questions is now standard in many departments. If a student's future depends on our judgment whether a statement in an examination question is true or false, then we can test only knowledge that is certain by today's standards. Patients have a right to know that doctors are not omniscient. We must accept that error exists and is widely prevalent. False knowledge and unacknowledged ignorance are not the only causes of medical error. Carelessness, tiredness, poor equipment and poor working conditions also contribute. If examinations penalised error and allowed admitted ignorance, then students and examiners might eventually develop critical attitudes to the knowledge that we now accept uncritically. Alan Dugdale Royal Children’s Hospital, Herston, QLD 4029 Australia
414
THE LANCET • Vol 358 • August 4, 2001
For personal use. Only reproduce with permission from The Lancet Publishing Group.
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Quinn TC, Wawer MJ, Sewankambo N, et al. Viral load and heterosexual transmission of human immunodeficiency virus type. N Engl J Med 2000; 342: 921–29. 6 Horton R. African AIDS beyond Mbeki: tripping into anarchy. Lancet 2000; 356: 1541–42. 7 WHO. WHO Tuberculosis Programme. Framework for effective tuberculosis control. Geneva: WHO, 1994 (WHO/TB/94.179). 8 Maher D, Chaulet P, Spinaci S, Harries AD. Treatment of tuberculosis: guidelines for national programmes, 2nd edn. Geneva: WHO, 1997 (WHO/TB/97.220). 9 Raviglione MC, Dye C, Schmidt S, Kochi A, for the WHO Global Surveillance and Monitoring Project. Assessment of worldwide tuberculosis control. Lancet 1997; 350: 624–29. 10 WHO. Global Tuberculosis Control WHO Report 2000. Communicable Diseases. Geneva: WHO, 2000 (WHO/CDS/TB/2000.275). 11 Mukadi YD, Maher D, Harries A. Tuberculosis case fatality rates in high HIV prevalence populations in sub-Saharan Africa. AIDS 2001; 15: 143–52.
12 Volmink J, Matchaba P, Garner P. Directly observed therapy and treatment adherence. Lancet 2000; 355: 1345–50. 13 Harries AD, Maher D. TB/HIV A clinical manual. Geneva: WHO, 1996 (WHO/TB/96.200). 14 Pozniak AL, Miller R, Ormerod LP. The treatment of tuberculosis in HIV-infected persons. AIDS 1999; 13: 435–45. 15 WHO. World Health Organization initiative on HIV/AIDS and sexually transmitted infections: safe and effective use of antiretroviral treatments in adults with particular reference to resource limited settings. Geneva: WHO, 2001 (WHO/HIS/2000.04). 16 Carr A, Cooper DA. Adverse effects of antiretroviral therapy. Lancet 2000; 356: 1423–30. 17 Bosman MCJ. Health sector reform and tuberculosis control: the case of Zambia. Int J Tuberc Lung Dis 2000; 4: 606–14. 18 Attaran A, Sachs J. Defining and refining international donor support for combating the AIDS pandemic. Lancet 2001: 357: 57–61. 19 Wood E, Braitstein P, Montaner JSG, et al. Extent to which low-level use of antiretroviral treatment could curb the AIDS epidemic in subSaharan Africa. Lancet 2000; 355: 2095–100.
Uses of error: False knowledge and ignorance I first became aware of error in the knowledge of students many years ago when I was teaching paediatrics in the University of Malaya. For example, when students were asked about the investigations needed to diagnose and manage a child with asthma, they would list everything from chest radiograph to serum folate. By listing everything they must include the correct answers and thus could not fail, even though some of the items listed were false, unnecessary, and perhaps dangerous. Examinations were marked as students expected, thus reinforcing their preconceptions. Traditional multiple choice questions (MCQs) expose the problem of false knowledge and error, but multiple true-false questions (MTFQs) reveal its extent. In these questions each part must be answered. With traditional scoring a student gets +1 for or a correct answer and 0 for omitting the answer or giving a wrong answer. The intelligent student has everything to gain and nothing to lose by guessing. This reinforced the message that correct answers passed exams, but wrong answers were irrelevant. Over the protests of the students and many teachers, I introduced MTFQs marked +1 for a correct response, –1 for wrong response and 0 for “I don't know.” I emphasised that saying, “I don't know”, was a definite statement about personal knowledge, so leaving an answer blank earned a score of –1. These questions showed that all students had some false knowledge. Interestingly, students had more difficulty in recognising that false statements were false, than in recognising true statements as true. I thought that these findings might be due to the alleged Asian proclivity for rote learning rather than understanding underlying principles. However, work in other countries has shown the same problems, with all students making some wrong responses but some students never admitting ignorance. A way of emphasising the danger of false knowledge and error is to incorporate penalties into examinations. Penalties for demonstrating false knowledge or error should make students critical of the knowledge they acquire and use. However, some teachers object to deducting marks and perhaps failing students on basis of error. It is also difficult to have all teachers agree on what is correct. When setting questions for examinations, we have had vehement disagreements even on anatomical structures, and the number of opinions about information needed for a firm diagnosis or the best management of a particular disease often equals the number of people discussing the matter. In the past teachers set papers or did clinical examinations without criticism from their peers, so these problems passed largely unnoticed. Peer review of written examination questions is now standard in many departments. If a student's future depends on our judgment whether a statement in an examination question is true or false, then we can test only knowledge that is certain by today's standards. Patients have a right to know that doctors are not omniscient. We must accept that error exists and is widely prevalent. False knowledge and unacknowledged ignorance are not the only causes of medical error. Carelessness, tiredness, poor equipment and poor working conditions also contribute. If examinations penalised error and allowed admitted ignorance, then students and examiners might eventually develop critical attitudes to the knowledge that we now accept uncritically. Alan Dugdale Royal Children’s Hospital, Herston, QLD 4029 Australia
414
THE LANCET • Vol 358 • August 4, 2001
For personal use. Only reproduce with permission from The Lancet Publishing Group.