스키마를 활용하여 교육해야 할 것인가? 무작위연구 근거(Med Educ, 2012)

스키마를 활용하여 교육해야 할 것인가? 무작위연구 근거(Med Educ, 2012)

Should we teach using schemas? Evidence from a randomised trial

Sarah Blissett,1–3 Rodrigo B Cavalcanti1–3 & Matthew Sibbald1–3

도입

INTRODUCTION

인지 부하 이론의 렌즈를 통해 보는 정보 과부하

Information overload through the lens of cognitive load theory

인지 부하 이론은 작업 기억의 유한성이라는 한계를 통해 학습의 어려움을 봅니다 .1 주제가 다수의 상호 작용적 요소를 포함하면 작업 기억이 압도되어 학습하기 어려워 질 수 있습니다. 전통적으로 많은 상호 작용 요소를 지닌 복잡한 과목은인지 부하를 줄이기 위해 각 요소를 개별적으로 제시하는 방식으로 교육하였다.1,2 예를 들어, 심혈관계 신체 검사를 학습하려면 학생들은 각 관련 진단에 대한 finding 목록을 습득해야합니다.

Cognitive load theory views the challenges of learning through the finite limitations of working memory.1 When a subject matter involves multiple interacting elements, it can overwhelm working memory and become difficult to learn. Traditionally, complex subjects with many interacting elements are taught by presenting each element separately to reduce cognitive load.1,2 For example, learning cardiac physical examination requires students to master lists of findings for each relevant diagnosis.

그러나 학생이 알 수없는 수축기 심잡음을 가진 환자를 만날 때, 그들은 기억력에 엄청난 도전이 되는 진단을 얻기 위해이 모든 정보를 통합해야합니다. 대안적인 접근법은 그 요소들이 어떻게 상호 작용 하는지를 명시 적으로 가르치는 것으로서, 이 때에는 정보를 스키마로 조직화하거나, 정보를 임상적, 병태생리학적 변인을 가지고 구분할 수 있는 진단적 표상으로 조직화하는 것이다. 스키마는 상호 작용하는 요소간에 가장 중요한 링크를 제시함으로써 인지 부하를 줄입니다.

However, when students face a patient with an unknown systolic murmur, they must integrate all of this information to arrive at a diagnosis, a task that presents a tremendous challenge to working memory. An alternative approach is to explicitly teach how the elements interact by organising information into schemas1 or representations of diagnoses distinguished by relevant clinical and pathophysiologic variables. Schemas reduce cognitive load by presenting the most important links between interacting elements.

스키마와 지식의 조직화

Schemas and knowledge organisation

초보자가 습득 한 지식 항목은 종종 격리된 사실isolated fact로 장기 기억에 저장됩니다. 격리된 사실은 다른 관련 정보와 연결되어 있지 않기 때문에 recall과 임상 문제에 적용이 어렵다. 이 정보가 임상 문제를 해결하는 데 유용하기 위해서는 임상 소견 및 개념을 중심으로 재구성해야합니다 .2 이렇게 하려면 학습자는 여러 가지 인과 관계 가설을 연결하고, 기본 개념에 대한 이해를 위해 자세히 설명elaborate해야 한다. Bordage는 이렇게 고도로 연결된 개념적 지식을 '컴파일 된compiled'것이라고 설명합니다 .3 스키마 그룹 진단은 관련 임상 및 병리학 적 변수에 따라 진단됩니다. 따라서 스키마를 제공할 경우, 스키마는 [구조화되고 임상적으로 관련성이 높은 방식]으로 정보를 제공하기 때문에, compiled knowledge를 개발하는데 도움이 될 수 있다.

Items of knowledge acquired by novices are often stored in long-term memory as isolated facts. Isolated facts are hard to recall and apply to clinical problems because they are not linked to other relevant information.3 In order for this information to be useful in solving clinical problems, it needs to be reorganised around clinical findings and concepts.2 This requires trainees to link multiple causal hypotheses and elaborate on them in order to build an understanding of the underlying concept. Bordage describes this highly linked conceptual knowledge as ‘compiled’.3 Schemas group diagnoses by relevant clinical and pathophysiologic variables. Therefore, the provision of schemas is hypothesised to aid in the development of compiled knowledge because schemas present the information in a structured, clinically relevant way.

스키마와 임상 추론

Schemas and clinical reasoning

초보자가 사용하는 진단 추론 전략에는 hypothetico-deductive 및 schema-based reasoning이 포함됩니다. Elstein 등 4)은 

• hypothetico-deductive reasoning을 임상의가 가설을 순차적으로 공식화하고 시험하는 과정이라고 기술한다. 

• schema-based reasoning은 주요 임상 기능을 사용하여 진단 세트를 포함 또는 배체하는 프로세스입니다. 

관측 연구에서 Coderre 등 5)은 초보 의대생들이 hypothetico-deductive 전략과 비교하여 스키마 기반 전략을 사용할 때 높은 진단 성공을 달성했다는 것을 발견했습니다. 더 높은 진단 성공의 이유를 스키마 기반 추론으로 돌리고 싶을 수 있지만, 스키마 사용은 임상 문제를 더 철저히 이해하고 있는 학생에게도 surrogate가 될 수 있다.

Diagnostic reasoning strategies used by novice learners include hypothetico-deductive and schema-based reasoning. Elstein et al.4 describe hypothetico-deductive reasoning as a process whereby clinicians formulate and test hypotheses in a sequential fashion. By contrast, schema-based reasoning is a process in which key clinical features are used to include or exclude sets of diagnoses. In an observational study, Coderre et al.5 found that novice medical students achieved higher diagnostic success when employing a schema-based strategy compared with a hypothetico-deductive strategy. It is tempting to attribute the higher diagnostic success to schema-based reasoning. However, the use of schemas may also be a surrogate for students with a more thorough understanding of the clinical problem.5

지식의 조직화와 추론 전략을 서로 연관시키기

Relating knowledge organisation and reasoning strategies

지식 조직화과 추론 전략은 서로 연결될 수 있다. [3,6] 

• 단순 암기를 통해 얻은 분산된 지식은 hypothetico-deductive reasoning을 강제한다. 

• 반대로, 정교한 인과 관계 네트워크를 갖춘, 고도로 컴파일 된 지식은 스키마 기반 추론을 촉진한다. 

따라서 스키마를 가르치는 것은 더 전문가와 유사한 형태로 지식을 조직화하도록 촉진하고 전문가와 같은 추론을 촉진하는 데 모두 유익한 효과가있을 수 있습니다.

Knowledge organisation and reasoning strategies are likely to be linked.3,6 Dispersed knowledge acquired through rote memorisation might force hypothetico-deductive reasoning. Conversely, highly compiled knowledge stored as elaborate causal networks may promote schema-based reasoning. Therefore, teaching schemas may have beneficial effects in both promoting more expert knowledge organisation and facilitating expert-like reasoning.

스키마-기반 접근법 테스트

Testing a schema-based approach

스키마 기반 교육에 대한 이전 연구에서는 테스트 점수가 향상되고 진단 정확도가 향상되었음을 확인했습니다 .9 이들 연구에서는 스키마가 스키마-기반 추론을 사용할 수 있도록 그에 적합한 구조로 정보를 제공한다는 점을 상기합니다.

Previous studies of schema-based instruction identified improved test scores and better diagnostic accuracy .9 These studies suggest that schemas provide information in a structure that enables the use of schema-based reasoning. 

경험이 많은 임상의들은 스키마 기반 교육은 학생들에게 배우지 않은 것에 대한 추론을 준비시킬 수 없다는 점에서 스키마 기반 교육을 비판했다. 8.9 심지어는 전문가들조차 낯선 문제에 직면했을 때에는 스키마적 추론을 포기하고 hypothesis testing을 사용한다. 10 스키마를 배운 초보 학생들은 hypothetico-deductive 접근법을 사용하여 자료를 탐색하지 않아도 된다. 그 결과, 학생들은 가르쳐주지 않은 진단에 부딪 힐 때 어려움을 겪을 수 있습니다.

Seasoned clinicians have been critical of schema-based instruction, arguing that schemas cannot prepare students to reason through an unlearned diagnosis.8,9 Even experts abandon schematic reasoning and adopt hypothesis testing when faced with an unfamiliar problem.10 Novice students taught with a schema have not had to navigate the material using a hypothetico-deductive approach. As a result, students may struggle when encountering untaught diagnoses.

우리는 무작위 시험에서 초보자들 사이의 심장 청진 기술 습득에 대한 전통적인 틀의 스키마와 비교하여 스키마 기반 교육의 효과를 테스트하는 것을 목표로 삼았습니다.

We aimed to test the effects of schema-based instruction in comparison with those of a traditional framework on the acquisition of cardiac auscultation skills among novices in a randomised trial.

METHODS

Population

Year 2 medical students at the University of Toronto were invited to participate. Students had previously completed two 4-hour sessions covering the components of the cardiac physical examination. All participants provided informed consent.

Design

Participants attended one of 14 sessions, each of which included up to five participants. Sessions were randomised into two categories to include 

• a control sample that received an instructional framework based on the traditional approach (Fig. 1) and 

• an intervention sample that received an instructional framework based on a diagnostic schema (Fig. 2). 

Both frameworks contained the same information. However, the organisation of the information differed. 

• The traditional framework (Fig. 1) was structured around individual valvular lesions and listed the 10 clinical features of each diagnosis in a table format. 

• The schema framework (Fig. 2) grouped diagnoses according to clinical features based on murmur location and timing (e.g. ‘apex beat’, ‘radiation’ and ‘character’ for a murmur heard at the apex).

Before the schemas were developed, we conducted a search for existing frameworks in the literature. This revealed two schemas that were inappropriate for the study. One schema used a finding not available on the simulator, hepatomegaly, as a key distinguishing feature of cardiac lesions, whereas the other was a cumbersome, long framework beyond the scope of a novice.18 Therefore, two experts with 10 years of experience in cardiac physical examination were consulted to develop an appropriate schema. The schema was revised based on pilot data.

The study was divided into four phases: 

• learning; 

• consolidation; 

• testing, and 

• retesting. 

The first three phases all occurred in the same session. Retesting occurred 2–4 weeks later. All written materials were handed to the facilitator at the end of the session to prevent any contamination between groups.

Learning phase

In groups of two to five students, participants were asked to deduce the diagnosis of four unknown cardiac lesions (aortic regurgitation, aortic stenosis, mitral regurgitation and ventricular septal defect) on the simulator using the assigned framework. A facilitator was available for technical troubleshooting, but did not participate in the learning process. Each participant was asked to record his or her diagnosis and the key features that had led to it. Once the group had finished, participants were given a written answer guide. The group was allowed 15 minutes to resolve any incorrect diagnoses or clarify examination features. 

This case-based, collaborative design was intended to foster learning while limiting the effects of instructional guidance to the framework provided. The four lesions chosen were derived from a survey of internists who identified them as key components of the curriculum for general practice.12 Learning worksheets were reviewed to ensure no misconceptions were learned using either framework. Each diagnosis was scored as correct or incorrect. Key features were categorised as correct features in the schema, correct features not in the schema, or incorrect features.

Consolidation phase

Participants were allocated 15 minutes to review the instructional framework prior to testing. They were allowed to discuss any learning difficulties within their group.

Testing and retesting phase

Participants individually completed a written test and then a practical test without the aid of their instructional framework. Participants were invited to undertake a repeat written test administered 2–4 weeks after the initial session. Retesting was limited to the written test by logistical constraints.

Written test

Participants completed a 19-question written test including single-response multiple-choice questions (MCQs), multiple-response MCQs and short-answer questions. The questions were divided into two groups. 

• The first group (n = 9) tested features which linked or distinguished diagnoses (structured knowledge questions). 

• The second group (n = 10) tested features of individual diagnoses (factual knowledge questions). 

Sample questions from each group are included in Table 1. Both groups involved diagnoses familiar to the participants from the learning phase (taught lesions) and not taught to the participants in the learning phase (untaught lesions). All tested diagnoses were present in both the structured and factual knowledge questions. The written test was marked by two researchers blinded to group allocation. Disagreement was resolved by consensus.

Practical test

Participants were asked to individually identify four unidentified lesions on Harvey

• Two of the tested lesions were taught lesions from the learning phase (aortic regurgitation and mitral regurgitation). 

• The remaining two lesions, aortic sclerosis and hypertrophic cardiomyopathy, were included on the instructional frameworks, but not in the learning phase (untaught lesions).

Data analysis

RESULTS

A total of 53 students participated in the study; 26 were assigned to the schema-based and 27 to the traditional-based instruction.

학습 단계

Learning phase

• 시간에 차이 없음
  There was no difference in the time used to complete the learning phase between participants assigned, respectively, to the schema-based and traditional instructional frameworks (45 ± 11 minutes and 39 ± 8 minutes, respectively; t12 = 1.2, p = 0.24). 

• 진단 정확도 차이 없음
  Accuracy in diagnosing the four lesions in the learning phase was similar between those assigned to the schema-based and traditional frameworks (98% versus 93%, respectively; t163 = 1.9, p = 0.06). 

• 전통적 방식으로 했을때, total feature, correct feature, incorrect feature 더 많음
  Students assigned to the traditional framework identified 

• more total features (4.4 ± 1.8 versus 3.8 ± 1.1; t210 = 2.9, p = 0.004), 

• more correct features not in the schema (1.4 ± 1.3 versus 0.1 ± 0.4; t210 = 9.9, p < 0.001), and 

• more incorrect features (0.2 ± 0.6 versus 0.04 ± 0.2; t130 = 3.1, p = 0.003) compared with those assigned to the schema-based framework. 

• 스키마를 받은 경우 스키마에 제시된 feature를 더 많이 찾음
  Students who received the schema identified significantly more features present in the schema (3.7 ± 1.1 versus 3.0 ± 1.3; t210 = 4.3, p < 0.001).

시험 단계

Testing phase

Written tests were scored independently by two raters with high inter-rater reliability (Spearman’s r = 0.961, p < 0.001). 

• 교육 방식에 따른 유의한 차이 있음
  There was a significant effect of instruction type on performance (F1003,3 = 17, p < 0.001). 

• 교육 방식과 문제 유형은 서로 상호작용 있음
  There was also a significant interaction between instruction type and question type (F1003,3 = 18, p < 0.001). 

스키마-기반 교육이 구조화된 지식 문항에서 더 높은 점수, 그러나 사실적 지식 문항에서는 더 높지 않음.
Schema-based instruction was associated with higher scores on structured knowledge questions (74% versus 55%; p < 0.0001), but not on factual knowledge questions (62% versus 62%; p = 0.93). 

2~4주 뒤 f/u
On follow-up testing 2–4 weeks later (n = 37, 70% of participants), these findings remained unchanged. 

• 교육 방식이 퍼포먼스에 영향 줌, 교육 방식과 문제 유형에 상호작용 있음
  There was a significant effect of instruction type on performance (F509,3 = 12, p = 0.001) and a significant interaction between instruction type and question type (F509,3 =5, p = 0.02). 

• 스키마 그룹이 구조화된 지식 문항에서 더 잘함
  Students in the schema group performed better on structured knowledge questions (62% versus 42%; p = 0.001), but not on factual knowledge questions (52% versus 48%; p = 0.41).

On the practical test, 

• 스키마-기반 교육이 더 높은 진단정확도
  schema-based instruction was associated with greater diagnostic accuracy (61% versus 26%; mean difference = 35%, 95% confidence interval [CI] 22–47; t205 = 5.40, p < 0.001). 

• 스키마-기반 교육이 가르친 lesion과 가르치지 않은 lesion 모두에서 더 높은 진단정확도
  Schema-based instruction was associated with greater diagnostic accuracy for both taught (77% versus 39%, mean difference = 38%, 95% CI 20–56; t102 = 2.26, p < 0.001) and untaught (44% versus 13%, mean difference = 31%, 95% CI 15–48; t89 = 3.75, p < 0.001) lesions. 

• For taught lesions, schema-instructed students identified the same number of overall features, more correct features in the schema, fewer correct features not in the schema and fewer incorrect features (Table 2). 

• For untaught diagnoses, schema-instructed students identified fewer overall features, fewer correct features not in the schema and fewer incorrect features (Table 2).

DISCUSSION

우리의 결과는 초심자들에게 심포지엄에서 스키마 기반 교육을 강력하게 지지합니다. 우리는 스키마로 지시받은 학생들이 전통적인 프레임 워크로 학생들이 지시 한 것보다 높은 진단 성공을 달성한다는 것을 발견했습니다. 26 %의 진단 정확도는 2 학년 학생의 진단 정확도에 대한 이전 평가에서 얻은 비율 (19-24 %)과 비교할 만합니다. 이는 이 그룹이 우리 설계에 의해 불공정하게 불리 해지지 않았다는 것을 의미합니다.

Our results provide strong support for the use of schema-based instruction in cardiac auscultation among novice students. We found that students instructed with a schema achieved higher diagnostic success than students instructed with the traditional framework. Of note, the 26% diagnostic accuracy achieved by the control group was comparable with rates achieved in previous evaluations of diagnostic accuracy among Year 2 medical students (19–24%),12,19 which suggests that this group was not unfairly disadvantaged by our design.

초보자에게는 스키마가 어떤 이점이 있습니까? 스키마가 지식 조직 및 진단 추론 전략을 수정하여 초보자에게 이익이된다는 가설은 우리 데이터에 의해 뒷받침됩니다. 필기 시험 결과는 (사실에 대한 진단적 지식을 변경하지 않고) 스키마가 구조화 된 지식의 양을 늘림으로써 조직화된 지식을 수정했다는 증거를 제공합니다. 효과의 크기 (38-40 %)는 이전 연구의 스키마와 유사하여 신상 문제의 점수를 30 % 향상시킵니다. 추론 전략이 직접적으로 측정되지는 않았지만 (언어 프로토콜로 압도적 인 초보자들을 두려워하여), 스키마를 배운 학생들은 자신의 진단에 도달하기 위해 스키마에서 발견한 feature를 보고할 확률이 높습니다. 이는 스키마를 배운 학생이 스키마 기반 추론을 많이 사용함을 의미합니다.

How do schemas benefit novices? The hypothesis that schemas benefit novices by modifying knowledge organisation and diagnostic reasoning strategies is supported by our data. The results on the written test provide evidence that schemas modified knowledge organisation by increasing the amount of structured knowledge without changing factual knowledge of diagnoses. The magnitude of the effect (38–40%) is similar to that in a previous study in which schemas were found to improve scores on nephrology questions by 30%.8 Although reasoning strategy was not directly measured (for fear of overwhelming novices with a verbal protocol), schema-instructed students were more likely to report features from the schema in arriving at their diagnosis. This suggests a higher use of schema-based reasoning by schema-instructed students.

스키마 기반 교육에 단점이 있습니까? 스키마를 사용하여 교육할 경우, 학생들이 아직 알려지지 않은 병변에 대한 진단 정확도가 낮을 ​​것으로 예상했는데, 이는 비-스키마 기반의 옳은 feature를 생성하기 어려울 것이기 때문이다. 전통적 교육을 받은 그룹이 가르치지 않은 병변에 대해 더 많은 수의 정확한 feature를 찾아냈음에도, 진단 성공이 더 좋지는 않습니다. 실제로 스키마 기반 지시 그룹은 진단 성공률이 30 % 높습니다. 두 가지 설명이 가능합니다. 

• 첫째, 전통적인 교육을 받은 그룹이 틀린 feature를 더 많이 찾아냈기 때문이다. 틀린 feature는 진단 추론을 틀리게 만들 수 있습니다. 

• 둘째, 스키마 기반 교육을 받은 그룹이 더 많은 스키마 기반 feature를 찾아냈기 때문이다. 스키마를 기반으로 찾아낸 feature는 진단 프로세스를 구분하는 데 도움이되므로, 비 스키마 기반 기능보다 진단 프로세스에 더 유용 할 수 있습니다.

Is there a downside to schema-based instruction? We anticipated lower diagnostic accuracy on untaught lesions among students instructed with schemas because they may be less likely to generate nonschema-based correct features. Although the traditional instruction group did generate a greater number of correct features for untaught lesions, this did not translate into higher diagnostic success. In fact, the schema-based instruction group had 30% higher diagnostic success. Two explanations are possible. 

• Firstly, the traditional instruction group identified more incorrect features. Incorrect features may have a derailing effect on diagnostic reasoning. 

• Secondly, the schema-based instruction group identified more schema-based features. Schema-based features may be more helpful in the diagnostic process than non-schema-based features as they help distinguish diagnoses.

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Med Educ. 2012 Aug;46(8):815-22. doi: 10.1111/j.1365-2923.2012.04311.x.

Should we teach using schemas? Evidence from a randomised trial.

Blissett S1, Cavalcanti RB, Sibbald M.

Author information

1

Department of Medicine, University of Toronto, Toronto, Ontario, Canada.

Abstract

CONTEXT:

Schema-based instruction may alter knowledge organisation and diagnostic reasoning strategies through the provision of structured knowledge to novice trainees. The effects of schema-based instruction on diagnostic accuracy and knowledge organisation have not been rigorously tested.

METHODS:

Year 2 medical students were randomised to learn four cardiac diagnoses using schema-based instruction (n = 26) or traditional instruction (n = 27) on a high-fidelity cardiopulmonary simulator (CPS). Students completed case-based learning in groups of two to five and underwent individual written and practical tests. The written test consisted of questions testing features that linked or distinguished diagnoses (structured knowledge) and questions testing features of individual diagnoses (factual knowledge). A practical test of diagnostic accuracy on the CPS was performed for two diagnoses present in the learning phase (taught lesions) and two untaught lesions. A majority of students (n = 37, 70%) voluntarily returned for follow-up written testing 2-4 weeks later.

RESULTS:

Learning time and accuracy did not differ between students on schema-based and those on traditional instruction. Students receiving schema-based instruction performed better on structured knowledge questions (p < 0.001) and no differently on factual knowledge questions (p = 0.7). Relative differences between groups remained unchanged on follow-up testing. Diagnostic success was higher in the schema-based instruction group for taught lesions (mean difference = 38%, 95% confidence interval [CI] 20-56; p < 0.001) and untaught lesions (mean difference = 31%, 95% CI 15-48; p < 0.001).

CONCLUSIONS:

Schema-based instruction was associated with improved retention of structured knowledge and diagnostic performance among novices. This study provides important proof-of-concept for a schema-based approach and suggests there is substantial benefit to using this approach with novice trainees.

© Blackwell Publishing Ltd 2012.

PMID:

 

22803759

 

DOI:

 

10.1111/j.1365-2923.2012.04311.x