We memorise a meaningless word “VIBGYOR” and associate its alphabets with colours of rainbow. We are encouraged by teachers and memory coaches to form our own mnemonics as aids to recall. Mnemonics do not have any standard; each person may form his or her own version. “BB Roy Of Great Britain Had A Very Good Wife” is used to remember the codes of 9 color bands on a resistor – followed with gold or silver to indicate accuracy. Outside the context, it is absurd. But, it served the specific purpose of mapping words to letters, in a context.
From very young age we pair ideas or small chunks of knowledge. We relate names with faces, voice with people, and meaning with patterns etc. Generally, we remember better by associating some objects and concepts with other objects and concepts.
Whereas mnemonics and acronyms help in memorising by association, metaphors help in understanding concepts by association. We associate well-known concepts with lesser known new topics consciously and subconsciously. Metaphors associate ideas at concepts level. In software development, Extreme Programming teams develop a common vision called “metaphor” to state how the program works. e.g., … such as “this program works like a hive of bees, going out for pollen and bringing it back to the hive” as a description for an agent-based information retrieval system.
We can effectively use metaphors in learning and teaching. A metaphor does not literally denote similarity between the referred concepts. What different people consider the core concepts can differ based on their own context and background. In the metaphor of “hive of bees” above, a person not from the software industry could consider the quality of hard work and discipline of the bees to represent the software application, which is not the meaning assigned by the software team.
When we introduce a metaphor in classroom or in a team, we have to understand and appreciate the core characteristics of the metaphor and how we map them to the concept under discussion. Once all the members of the team understand the metaphor similarly, it becomes very effective in getting a deeper meaning to the new concept we are learning. The metaphor then helps in understanding and reminding the concept and making communication more effective.
Let us consider commonly used thermometer and thermostat.
Manufacturing a thermometer is more complex than manufacturing a thermostat. The markings are precise and accurately calibrated, the glass is fine and delicate, and the mercury in it shines in uniform hair-thin capillary tube. We need a good factory setup to manufacture thermometers. We cannot repair one if broken.
A thermostat depends on a simple bimetallic strip. Thermostat cuts-in and cuts-out an electrical contact with change in temperature around it. It is not finely calibrated, not enclosed, and looks crude compared with a thermometer. Using simple tools like pliers, screw driver and soldering iron, we can repair one for minor damages.
Similarities: Both these devices sense the temperature around them. They are widely used in several applications.
Differences: They differ in their responsibilities and accountability.
- A thermometer records and displays the temperature. Someone has to read the temperature and take appropriate action. The thermometer has no context and knowledge. It has very little capability though it is fairly efficient in the little it does.
- A thermostat acts on the information it has by cutting in or cutting out the power supply to the appliance. It has knowledge, understands the context and acts on the information it has. It does not depend on external agency to act on the situation.
If the refrigerators and air-conditioners simply told us to read the temperature and then turn them on or off based on our discretion, we would not be able to sleep at night or to leave home leaving them operating. Electric irons would burn the clothes if we were not careful to monitor the heat. Industrial gadgets have their own stories of efficiency and effectiveness by using thermostats.
Teaching students in B-Schools I use this metaphor to explain the importance of ownership and accepting that timely action, even if not precise, is more important than being passive about it or disowning responsibilities by reporting to the superiors. From the perspective of a manager, it demonstrates the importance of delegating responsibilities and matching authority to subordinates. Centralising power and expecting only reports from the subordinates does not allow growth of subordinates, and does not help the efficiency of the organisation.
While teaching object oriented design, I use the metaphor to explain how to build smart objects like the thermostat, how to distribute intelligence and responsibilities evenly across the system, concept of coherence and coupling, and the real meaning of modelling with encapsulation.
I use the example while discussing with teachers and students in schools and with young people seeking my advice.
After discussing the metaphor in a class, I overheard participants near water cooler telling each other “don’t be a thermometer!” I felt rewarded!
More metaphors later.