This was originally to be submitted to Michele Martin's post as a comment but due to its length I decided to post it here. In no way is there any intent to upstage Michele's post on How Do You Use Metaphors For Learning?
The word as a written metaphor:
The written word, being composed of symbols, is itself a metaphor for the spoken word that’s made up of sounds. Already once removed from the sense of the uttered sound, the written word has to be interpreted before it’s understood.
Despite the thousands, perhaps millions of written words at our disposal, people still invent words – all the time – some of which are never written. Yet for some people the reading of a word new to them can cause them real problems. They may decide, for instance, that a new word has been miss-spelt, relating it to another familiar word, and may lose entirely the sense connoted by the context that it is in.
The best metaphor is spoken:
Exponents of our language such as Shakespeare and Hopkins invented words to convey meanings that could not be conveyed by existing words. Shakespeare is given credit for inventing thousands of words that are in use today. The distinction between Shakespeare’s and Hopkins’ is that Shakespeare’s were heard by his audience, not read by them. Perhaps it’s for this reason that he was so successful in making in-roads to the language with his own words, though the quantity of his writing would also have contributed to achieving this.
So in terms of success, the suggestion is that a good metaphor should be spoken first – a difficult task when using written words to describe a metaphor.
What is the composition of a metaphor?
Wikipedia describes the metaphor in detail and outlines how the metaphor relates to what it's supposed to convey. A metaphor can be thought of as having two parts, the target and source (other terms are used for these - tenor and vehicle). The target is the subject to which attributes are ascribed. The source is the subject from which the attributes are borrowed.
It also speaks of the ground and the tension of a metaphor. The ground relates to what is similar between the target and source. The tension relates to the dissimilarities. The dead metaphor is explained as one that doesn’t work – “the sense of a transferred image is not present . . . dead metaphors, by definition, normally go unnoticed.”
When a metaphor is used for learning, it follows that it must have life. Dead metaphors, whatever application others may say they have, are unlikely to have much use to the teacher. To have life, the metaphor must have ground, sufficient so that the imagination is invoked and as little tension as permits the ground to be envisaged.
Mathematics is steeped in metaphor and its symbols are often chosen with metaphor in mind. It’s no accident that the Greek alphabet is so widely used in this discipline, for its letters are also steeped in metaphor – they are the alpha and omega of metaphorical symbolism.
Choosing metaphors that have their source within the scientific discipline can be useful but it can also cause problems. It is often important that the mapping of the source components of a metaphor is clear and accurate. Unless the source components are clearly understood there is danger of poor mapping onto the target that could result in a confusing metaphor. There are also many concepts in Science that are difficult to understand. This is why scientists and science teachers so often use visual models and tangible ones. Not only are they helpful for learners of Science, but they are also useful tools for communicating scientific ideas with others.
Metaphors can mean less learning:
Models like the particle, the wave, the balance and the wheel are often used in Science since these sources are already familiar and understood. With demanding concepts come difficulties associated with understanding and the teaching of them. In attempting to find a model, sometimes the metaphor that’s chosen is as difficult to understand as the concept itself. So it becomes redundant and little is achieved through its use.
Examples of this are attempts to use metaphors for the processes of mitosis and meiosis, biological terms applied to different processes of cell division. Because of the similarity in the look and sound of the words describing these processes there is often confusion as to their application to the related processes.
In introducing these processes to students the teacher has to resort to a related, but nonetheless simple, metaphor in order to convey some understanding of the difference between the terms.
For someone who has been introduced to the concepts of mitosis and meiosis and understands them, for instance, the metaphor ‘sex’ can be of some use. The words ‘sex’ and ‘meiosis’ both contain the letter ‘e’. Meiosis is the special division of cells in the gonads that gives rise to the sex-cells (or half-cells) sperm and ovum.
Mitosis is the term used to describe cell division giving rise to two whole cells. Though it’s a process used in reproduction, it is entirely different from the reproductive processes that involve meiosis. The word mitosis does not contain the letter ‘e’.
In this case, the association of meiosis with the word ‘sex’ related to the context of its use through a common letter ‘e’ can be used to draw the distinction between two similar words mitosis and meiosis. But the metaphor is contrived and is really not an elucidating one, for it conveys only a way of telling which term applies to which process. It does not convey a useful meaning that helps a learner understand the individual processes.
A simple model for metaphor:
Occam’s Razor is a good metaphorical tool that’s helpful when choosing or inventing a metaphor for use in a learning environment.
It says that the number of things needed to explain anything should not be increased more than necessary.
Even the introduction of a metaphor, by its occurrence, is increasing the things that must be assimilated by the learner. If the learner must first discover and understand the source, especially if it encompasses difficult concepts to begin with, the target simply disappears from sight. The whole reason for using the metaphor is lost. So it makes sense that if a metaphor is to be used, it should have a source that is well known and understood. This makes for one less learning task that has to be done to reach the target.
What makes a good learning metaphor?
To find examples of the use of splendid metaphor and how it is employed we need look no further than the successful poets. It is no coincidence that in the traditional teaching of the meaning of metaphor there is often reference to the works of the poets. Their words ring clear, simply from the common nature of their craft. They are well acquainted with the need to find idea from familiar source to target what they wish to convey.
I think that this should apply in a similar way to metaphors that may be chosen as possible learning tools.
The fine delight that fathers thought; the strong
Spur, live and lancing like the blowpipe flame,
Breathes once and, quenched faster than it came,
Leaves yet the mind the mother of immortal song.
Gerard Manley Hopkins
Ka kite anō
Catch ya later