Using Metaphors, Analogies and Similes as Aids in Teaching Pathology to Medical Students

Rani Kanthan, M.D. and Sheryl Mills, M.Ed.

Colleges of Medicine and Education University of Saskatchewan


Metaphors, analogies, and similes bridge the known to the unknown, and alter the conceptual system of existing knowledge by modifying and strengthening its associations. Although the use of metaphors, analogies, and similes is pervasive in our language, not much has been written about its use as a potential active teaching strategy in medical education to explain complex or abstract concepts. Metaphors, analogies, and similes were used intentionally in two consecutive years of an undergraduate pathology course for medical and dental students for two purposes: a) to communicate and understand complex concepts such as those related to acute and chronic inflammation, thrombosis, embolism and infarction; and b) to provide practice for students to become better communicators of complex medical concepts using these strategies. Students found that working with metaphors, analogies and similes enhanced and aided their learning, and challenged their communication skills. The unexpected impact of creating visual metaphors had a unique potential for improving recall of information. The discussion and negotiation of metaphors can be used in medical education as an effective teaching strategy to augment communication skills towards a better understanding of complex medical concepts. This, in turn, may aid students in becoming effective communicators with their prospective patients.


Although the use of metaphors, analogies, and similes is pervasive in our language, not much has been written about its use as a potential active teaching strategy in medical education. A metaphor is defined as a figure of speech in which a word or phrase that ordinarily designates one thing is used to designate another, thus making an implicit comparison, as in “a sea of troubles” or “All the world’s a stage.”1 An analogy on the other hand shows similarity in some respects between things that are otherwise dissimilar and a comparison is based on such similarity as in “the operation of a computer presents an interesting analogy to the working of the brain.”2 In contrast, a simile is a figure of speech in which two essentially unlike things are compared, often in a phrase introduced by like or as, as in “How like the winter hath my absence been” or “So are you to my thoughts as food to life.”3 In the context of this article and in our teaching, we use the terms metaphor, analogy, and simile interchangeably.

The essence of a metaphor is the process of understanding and, perhaps, experiencing one kind of thing in relation to another.4 Metaphors can facilitate communication by providing something tangible in terms of other more familiar concepts to an otherwise abstract complex medical concept. Metaphors also have the potential to bridge understanding between the known and the unknown, and alter the conceptual system of existing knowledge to modify and strengthen its associations. As such, metaphors may be used as an effective tool to enhance the understanding of complex and abstract patho-physiological processes.5 Metaphors can also create rapport2 with students when a known concept, something from their world, is linked with something foreign. Well chosen metaphors provide a connection to that which the students already knows, and offers order to the chaos of the new language and unfamiliar concepts.6 Perceived order enhances learning. Aristotle compared metaphors to puzzles, and as puzzles, metaphors engage us in solving how one thing is like another.4 It is this engagement in the process of resolution that makes the use of metaphors so valuable in conveying and understanding complex concepts. This is particularly valuable in the case of medical education wherein new vocabulary with highly refined language is being introduced.

Although some metaphors can be more obfuscating than illuminating, there are simply degrees of appropriateness in the metaphor encapsulating the qualities of the new concept that is being learnt.4,7 When students develop their own metaphors for new concepts (providing they have a fairly good understanding of the concept), they further strengthen

their understandings because they are (a) negotiating the appropriateness of the metaphor they are working with, and (b) arranging their understandings in personally meaningful ways.5

Metaphors were used intentionally in teaching undergraduate pathology to medical and dental students for two consecutive years (Figure 1). The principle intentions included:

  1. Incorporating open-ended, forced, and visual metaphors to teach complex concepts (e.g. acute and chronic inflammation, thrombosis, embolism and infarction);
  2. Involving students in a creative dynamic thought process to enhance understanding of such complex medical concepts; and
  3. Providing students with a forum to practice the communication of complex medical concepts through the joint exploration of metaphors, analogies, and similes in terms of other things with which they were more comfortable and familiar.


This study was initiated and carried out by the course coordinator in keeping with her ongoing interest in developing a repertoire of instructional methodologies that engage medical students in their own learning. The instructor has worked on this project with a coach and co-author of this paper, a doctoral candidate in Educational Administration, as part of their on-going interest in active learning in the medical curriculum.7

This instructor, who intentionally incorporated metaphor, analogy and simile, taught 13 of the 22 classes in the Year 2003 and 12 of the 22 classes in the Year 2004. In both years, these sessions formed a block series of lectures occurring from the beginning of the course to the midterm exam thereby maintaining continuity of communication. During the first year of study there were 88 students enrolled in the 6-credit course: 60 second year medical students, 26 second year dental students, and 2 graduate students. During the second year of study there were 63 second year medical students, 27 second year dental students, and 2 graduate students.

Instructional Metaphor Examples
The instructor first modeled the use of metaphors by peppering her traditional lecture with explicit metaphorical and analogous examples:

  1. For inflammation, the instructor used a sports analogy. Although starting with tennis, a game she is familiar with, she quickly made a switch to football and hockey when it became apparent that the intricacies of tennis were not familiar to many students. She discussed the medical concepts of exudation, transudation, edema, and pus by using the sports vernacular and language (i.e. game strategy plans). She indicated how the game strategies paralleled those of the body in inflammation in terms of:

    • where the sport or game was played. The vascularized connective tissue became the playing field;
    • the teams were Team A (the circulating cells in vessels ?neutrophils, eosiniphils, basophils, and platelets) and Team B (the connective tissue cells — mast cells, resident macrophages, and lymphocytes); and
    • the extracellular matrix, composed of structural fibrous proteins, adhesive glycoproteins and basement membranes, became the “reserves” on the “bench.?

    The instructor likened the “quick kill” of acute inflammation to a “blow out” in hockey as opposed to chronic inflammation that resembled repeated overtimes in hockey. In tennis, chronic inflammations, like persistent infections and autoimmune diseases, were described as more closely resembling the prolonged agony of a 5 set tennis match with alternating deuce/match points, while, acute inflammation was likened to winning in three straight sets.

  2. The pathogenesis of thrombosis was demonstrated using a toilet roll for a vessel lumen with “Smarties” as cells– white blood cells, red blood cells, and blue platelets — stuck to its interior. This actual model was held up as it was created and explained in class. A glue stick was used to “injure” the endothelium so that different cells could “stick” to the inside. The fibrin mesh was illustrated with red “Twizzlers.? A recipe card for thrombosis was shown concurrently. (Figure 2)
  3. For embolism, the students were asked to create three scenarios for the “perfect murder” using the principles of embolism.
  4. Thrombus / Infarction became a plumbing blockage or the “loo” getting blocked. Students were presented with a situation where a tennis ball had found its way into the “S” shaped bend of the toilet bowl. As it absorbed water, it caused the flush to act in unpredictable ways. The ball intermittently obstructed the “flow” with the final result being a complete breakdown and an almighty flooding mess. This process was likened to the fate of a thrombus resulting in the various possibilities ranging from no effect to intermittent blockage to full blown infarction with complete breakdown of normal structure and order.

Student-developed Metaphors
As classes progressed, students were asked to work in small, informal groups to develop visual and verbal metaphors that linked the pathology concepts being presented in the lecture to common visual or verbal concepts. As well as providing a break in the flow of lecture information, it gave students an opportunity to reflect, discuss, and incorporate new concepts into their existing conceptual paradigms. The students had time in class to negotiate metaphors that illustrated the concept through these dialogues. For the verbal metaphors, students were asked to consider how the concept was like x and not like x. In the “open-ended metaphor,? students were given the abstract medical concept, and were free to choose and develop the analogue for the concept. For “forced” metaphors, all students worked with the same analogue. They were given both the concept and the other half of the metaphor to which they had to provide supporting evidence for the analogue.

?Visual metaphors” were developed and explained through drawings and pictures that were not intended to be literal representations of the concept. It was hoped that exploring and negotiating the characteristics of new complex medical concepts through discussion and dialogue with metaphors would help to cement these ideas while providing a model that could be used to clarify medical complexities with patients in the future. Students worked in groups to choose an analogue, discuss and negotiate its merits, and then draw it. The drawings were collected at the end of the class and reviewed by the instructor. In this way, the instructor could clear up any misconceptions. Samples of the student responses to the activities were often shared with the large group at the beginning of the next class. Students requested to hear how others had responded and sharing these responses seemed to spark enthusiasm in class.

Data Gathering.
We gathered student responses to the inclusion of metaphors at different points in each class as part of our on-going investigation into the inclusion of active learning. As the instructor had no further direct teaching responsibilities in this course after the midterm, in both years, the students’ perceptions of incorporating analogy and metaphor were gathered in the Midterm Evaluation/Reflection questionnaire7 at the midterm exam. In Year 2003, the questionnaire included room for open-ended responses about the positive, the negative, and the interesting aspects of the course. There was also space for “other” comments. In Year 2004, the questionnaire had no open-ended questions. The questionnaires were collated and the comments were

analyzed using simple measures such as median, percentages, averages, and range of student comments that were categorized for over-riding themes. Another form of evaluation included a question on the midterm exam directly testing the application of metaphor to the material covered by this instructor. The students’ final marks for years 2000-2003 (Table 1) were comparable. This was in keeping with the performance at the midterm as published previously.7 Therefore, we concluded that the changes in instructional styles did not adversely affect the students’ performance as a whole.

In Year 2004, the data collected from this second group of students was more extensive than from the first. It was as a result of the responses of the first group of students that we decided to try this method again and investigate more thoroughly. In addition to the questionnaire at the midterm exam, feedback was garnered from the students in the Year 2004 section halfway to the midterm by asking what they would like to see stopped (STOP), what they would like the instructor to add (START), and what they would like to see continued (CONTINUE).7

At the midterm examination the use of metaphors, analogies, and similes as a communication tool for explaining complex medical concepts to patients in clinical practice was also evaluated by written responses generated to short answer questions (SAQs) as seen in the example below:

A 15-year old lad suffering from familial hypercholesterolemia is referred to your clinic for a consultation. Using verbal and / or visual metaphors as practiced in class:

a)Summarize the key concepts of the pathogenesis of atherosclerosis (2 marks); and

b)Explain the etiopathogenesis of this disease including risk factors (2 marks).


The following are discussed in this section:

  1. Student-developed metaphors;
  2. Student reactions to the use of metaphors as an instructional tool;
  3. The potential of using metaphor as a communication tool; and
  4. Challenges and risks involved in using metaphors.

      1. Student-developed metaphors. Students in both years participated in the classroom activities with varying degrees of enthusiasm. There appeared to be engagement in the activities and a good deal of productive “buzz” in the lecture theatre during the activities.

        Open-ended metaphors. When students were asked to consider three ways in which acute inflammation was like x and three ways that acute inflammation was not like x, they devised their own metaphors based on things they knew and valued, and were thus able to arrange their learning experiences by strengthening understanding by linking something from their world with the newly presented abstract concepts in personally meaningful ways.5 The students’ metaphors for acute inflammation clustered around 6 main themes:

        1.interpersonal dynamics (including sex/dating)35%

        2.war and other forms of conflict18%

        3.regular daily activities16%

        4.sports (although they had been steered away from this)14%

        5.natural phenomena11% and concerts 5%

        A few examples of student-developed open-ended verbal metaphors for acute inflammation are illustrated in Figure 3. Students enjoyed hearing what their peers had created at the beginning of the next class and this also served as a review of the concepts of the previous day’s class.

        Forced metaphors. In class, after small “Timbit” donuts were distributed and enjoyed, students were asked, “How is inflammation like a Timbit? How is inflammation not like a Timbit?? They gave a range of responses (Figure 4). The students, however, seemed less enthusiastic towards this activity in comparison to the creation of open-ended metaphors as revealed in their comments, their hesitation in engaging in the activity, and their overall reluctance to think outside the conventional framework. There may be several reasons for this:

        • The comparison may not have resonated with the students.
        • The technique may have become over-worked.
        • The comparison may not have risen to the potential for it to involve them in working to comprehend the connections.4
        • They may have felt stifled, trapped, or uncomfortable by the “forced” choice.
        • The students may not have understood either half of the metaphor well enough upon these initial introductions to make comparisons and see relationships.8
        • There may have been a feeling that there was a “right answer” that they were trying to guess, rather than, feeling free to explore and develop possibilities as they had done with the open-ended metaphors.
        • Developing open-ended metaphors was a creative activity in comparison to the forced metaphors where students may have felt “restricted.?

        Visual metaphors. There was a mixed reaction to “drawing” metaphors. There was some “shock” and surprise that this could happen in a university class. There was also enthusiasm for doing something that seemed to be “play.? The visual metaphors that students developed for thrombosis, embolism, and infarction fell into 3 main categories: gardening, plumbing, and construction. Figure 5 illustrates examples of their work.

      2. Student reactions to the use of metaphor as an instructional tool. Students in both years reported on their learning, and about using metaphors as an instructional and communication tool.

        Year 2003. Student responses to analogy and metaphor were varied. Students were asked at the midterm what were the positives, the negatives, and the interesting aspects of the course. Although other comments were directed toward class structure in general, many comments were directed specifically at the inclusion of analogies and metaphors. Of the 39 positive comments, 8 (20%) specifically mentioned analogy and metaphor. Of the 77 negative comments, 6 (8%) specifically mentioned analogy and metaphor, and of the 64 “interesting” comments 18 (28%) specifically mentioned the benefits of analogy and metaphor for “fixing” the

        understanding of a medical concept for easy recall at the midterm examination. Many felt that if they drew the concept or were involved in the discussion of the drawing, it helped them to recall the information much easier. However, students were divided in their reactions to being asked to actually “draw” in class. Although only one of the comments was directly negative (?I’m paying $10,000 to draw cartoons?), responses ranged from “interesting” to “threatening” to feeling that it was a waste of their time and that the activity was “childish.?

        Students explored metaphors in a very different way when they started to draw. They were engaged in a process to clarify their drawings with their peers. When students explored and negotiated metaphors with their peers to reach a consensus, they were in a creative realm which was instrumental in forming new constructs.9 Negotiating helped them accurately explain the medical concept to the best of their abilities. A metaphor conveys a lot in a succinct way; unpacking the metaphor illuminates the “ineffable.?4 Metaphors generate meaning and aid in understanding anyway,4 and a visual metaphor has the added advantage of being “visual.? Negotiating this through dialogue and discussion with their peers may have also contributed to the learning impact of the visual metaphor.

        Year 2004. At the midterm evaluation, response to the statement that analogies introduced by the instructor helped them understand and consolidate the content more thoroughly was as follows (n=86): 17 students “strongly agreed” (20%), 47 students “agreed” (55%), 15 “disagreed” (17%), and 7 students “strongly disagreed” (8%).

        Due to the resistant dynamics in the group, these students were not asked to create visual metaphors in the classroom. It was suggested that they might try the technique on their own to see how it worked for them.

      3. The potential of using metaphor as a communication tool. Year 2004 students were asked if they had learned any new techniques that might aid in explaining complex

        medical concepts to their patients in the future. Of the 86 responses, 8 “strongly agreed” (9%) (e.g. “relating topics to real life situations—helpful for explaining to patients.?), 44 “agreed” (52%), 27 “disagreed” (31%), and 7 “strongly disagreed” (8%). All students attempted the midterm exam question that evaluated this skill. Developing skills in using metaphors at this stage in their careers may help them in the future when they negotiate appropriate metaphors to explain complex medical concepts succinctly and accurately to their patients. The use of metaphors could be considered to be an essential part of the communication skill development and competencies for medical students.
      4. Challenges and risks involved in using metaphors. When one thing that is unknown is linked to something that is known, the learner has the benefit of previous understandings and an existing conceptual template in which to embed the new concept. A well-chosen and developed metaphor can illuminate a difficult concept but a weak metaphor may confuse the learner. An ill-fitting, inappropriate metaphor can actually disengage learners5 by leading them down a conceptual pathway of misunderstanding. It is, therefore, important to clarify the metaphors learners develop to be certain that they are on the “correct” conceptual pathway of understanding.

        Independently, a few students made the same observation. Although they felt that they understood the “large picture” of the new concept, they did not feel that they were familiar with the details that made up the larger picture (e.g. “The visual metaphors actually did help me remember basic concepts, but not the fine details?). This has implications for future applications. Global thinking and understanding of a complex medical concept may not lend itself to ultimately putting the concepts into practice. If not checked, students may end up having their understanding of the detailed dynamics that contribute to the big picture overshadowed by a more thorough understanding of the big picture itself.

        Students will be aware and conscious of their own use of metaphors and can later tailor this usage to individual patients based on a patient’s personal and cultural values and unique presentation of their disease. Just as the instructor changed metaphors “midstream” moving from the less familiar game of tennis to the more familiar game of hockey in explaining acute inflammation, appropriate metaphors that resonate with individual patients are critical.

        An instructor’s metaphoric skill, imagination, and sensitivity are important in creating a solid learning platform during this demanding period of medical students’ lives. It is useful in the two-way communication that facilitates better understanding of the nature of unshared experiences in the transfer of knowledge and the creation of meaningful learning relationships. In this two-way instructional-communication process, great heights of learning and understanding can be potentially achieved with mutually resonant metaphors and methodologies. Instructors’ individual personalities and teaching styles will largely determine the various formats of metaphor exploration. Likewise, students have differing learning styles which will have a significant impact on which methodologies will be useful to them. We recommend incorporating varied instructional strategies of which the intentional use of metaphors, analogies, and similes as an additional method for medical educators to draw upon to accommodate these differences.

        In order to suitably tailor the metaphors they use, clinicians and teachers require listening skills to pick up on the specific nuances and language of metaphors used by their patients and students. Metaphors used and practiced in learning can then be transferred to clinical situations to assist in the mutual understanding of the underlying disease processes that may cause illnesses.


      Metaphors can serve as an effective instructional teaching tool for understanding complex medical concepts. In this observational study the salient features observed were:

      1. The discussion and negotiation of mutually resonant metaphors can be used in medical education as an effective teaching strategy to augment and enhance interpersonal and communication skills for a better understanding of complex, abstract medical concepts.
      2. It is important for the medical teacher to choose appropriate metaphors so students understand the concepts correctly as inappropriate metaphors can lead students down conceptual pathways of misunderstanding.
      3. Creating visual metaphors may have a unique potential for improving recall of information; when students drew the “concepts,? both the activity and the concepts “stuck” in their minds.
      4. Some students found that working with metaphors, analogies and similes enhanced and aided their learning.
      5. Exposure to and the practice of using metaphors, similes, and analogies may help students to become effective communicators in their future clinical practices.


      We, the authors wish to thank Ms Carla Merritt, Mr. Todd Reichert and Ms Mitch Hesson for all their help in the production of the figures for this manuscript.


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