The third job of preparation, after selecting the relevant material, and organizing it in a clear and simple structure, is to form the details into a coherent argument. Every talk has a case to argue, unless it has no more structure than a telephone directory. The way this case is argued, the way the details are marshalled as evidence for the points being made, is an important part of the planning.
The first point is that you cannot make the argument complete, and prove every point and detail. Spoken argument can only sketch the outlines of the case. It gives an emphasis and immediacy, through personal involvement, and immediate feedback from the audience, but it does not give a forum for the fine points and the mechanics of scientific proof. Speaking can only offer the bold outlines of proof, not the inner workings, of the argument. The details are better written down. So if you have to present a case which has a detailed proof, you must summarize, give a few salient details, and refer your audience to the published papers, or internal reports.
Skimming over the details of reasoning does not relieve the speaker of the need to be accurate. It is wise to avoid apparently spurious argument; the audience will spot it. Ogden and Richards warn about the ‘process of ‘lubrication’, the art of greasing the descent from the premises to the conclusion.’ While such a process may seem attractive, you should not imagine that the audience is less sharp, just because they have fewer details. They have more time to think, and will be able to bridge the gap between generalizations, to work out the details for themselves. Unless the story hangs together, they will not believe what you say. Accuracy is just as important in spoken presentations, as it is in published papers.
The art of conveying an argument in a spoken presentation lies, then, in the selection of the examples to use. Most scientific arguments are based on induction. But you should never try to offer complete induction, listing tables of figures and results. In a talk you can only state the hypothesis, use a few illustrative examples of the kind of results obtained, and state the conclusions. Of course, you must make sure that the examples you give are typical. One way to do this is also to give exceptions to validate the examples, and forestall criticisms.
The old adage is: ‘The exception proves the rule’. This saying, incidentally, is usually misunderstood, because ‘proof means test, as in ‘proof spirit, or ‘proving’ a gun. The adage means that the rule is checked by the exception. Can the exception dent or explode the rule you are trying to prove? Will the rule survive? The purpose of giving exceptions is to see whether the exception can be explained away as an irrelevance, not a true exception, or an example of some other rule altogether. If not, then the rule must of course be modified to take account of the facts which it does not satisfactorily explain.
The psychology of audiences requires that an attempt is made to illustrate a rule, or general conclusion, with obvious and typical facts, as well as apparent exceptions. The speaker’s job is to allay doubts, and calm suspicions, not to produce cast iron proofs. He has also to explain and clarify the rule, and exemplification is often the best way of explaining, as well as the best way of justifying, a conclusion. But as speaker you should never lose sight of the role of examples as aids to the audience, rather than as elements in a scientific method. If you keep this distinction in mind, you will be able to persuade yourself when preparing the talk that not all details, facts and figures are relevant to the task. A carefully selected set of illustrative examples is all that the structure of the reasoning requires in verbal presentation.
In considering the type of examples to choose, the speaker must find what will be easiest for the audience to understand in the limited time available. Thus, there is evidence that human beings prefer direct proof to indirect proof. That is to say they prefer to be shown that something is the cause, not that all the other possibilites can not be the cause. This seems to be because of the universal tendency to cognitive economy: in other words people like the simple and direct route to a conclusion, rather than one which requires sustained attention, a sharp memory, and active deduction. So the wise speaker will construct his argument as a direct, not an indirect, proof. The aim should be to give strong, simple arguments, which offer clear, uncomplicated reasons, not elaborate and intricate analyses.
The first point is that you cannot make the argument complete, and prove every point and detail. Spoken argument can only sketch the outlines of the case. It gives an emphasis and immediacy, through personal involvement, and immediate feedback from the audience, but it does not give a forum for the fine points and the mechanics of scientific proof. Speaking can only offer the bold outlines of proof, not the inner workings, of the argument. The details are better written down. So if you have to present a case which has a detailed proof, you must summarize, give a few salient details, and refer your audience to the published papers, or internal reports.
Skimming over the details of reasoning does not relieve the speaker of the need to be accurate. It is wise to avoid apparently spurious argument; the audience will spot it. Ogden and Richards warn about the ‘process of ‘lubrication’, the art of greasing the descent from the premises to the conclusion.’ While such a process may seem attractive, you should not imagine that the audience is less sharp, just because they have fewer details. They have more time to think, and will be able to bridge the gap between generalizations, to work out the details for themselves. Unless the story hangs together, they will not believe what you say. Accuracy is just as important in spoken presentations, as it is in published papers.
The art of conveying an argument in a spoken presentation lies, then, in the selection of the examples to use. Most scientific arguments are based on induction. But you should never try to offer complete induction, listing tables of figures and results. In a talk you can only state the hypothesis, use a few illustrative examples of the kind of results obtained, and state the conclusions. Of course, you must make sure that the examples you give are typical. One way to do this is also to give exceptions to validate the examples, and forestall criticisms.
The old adage is: ‘The exception proves the rule’. This saying, incidentally, is usually misunderstood, because ‘proof means test, as in ‘proof spirit, or ‘proving’ a gun. The adage means that the rule is checked by the exception. Can the exception dent or explode the rule you are trying to prove? Will the rule survive? The purpose of giving exceptions is to see whether the exception can be explained away as an irrelevance, not a true exception, or an example of some other rule altogether. If not, then the rule must of course be modified to take account of the facts which it does not satisfactorily explain.
The psychology of audiences requires that an attempt is made to illustrate a rule, or general conclusion, with obvious and typical facts, as well as apparent exceptions. The speaker’s job is to allay doubts, and calm suspicions, not to produce cast iron proofs. He has also to explain and clarify the rule, and exemplification is often the best way of explaining, as well as the best way of justifying, a conclusion. But as speaker you should never lose sight of the role of examples as aids to the audience, rather than as elements in a scientific method. If you keep this distinction in mind, you will be able to persuade yourself when preparing the talk that not all details, facts and figures are relevant to the task. A carefully selected set of illustrative examples is all that the structure of the reasoning requires in verbal presentation.
In considering the type of examples to choose, the speaker must find what will be easiest for the audience to understand in the limited time available. Thus, there is evidence that human beings prefer direct proof to indirect proof. That is to say they prefer to be shown that something is the cause, not that all the other possibilites can not be the cause. This seems to be because of the universal tendency to cognitive economy: in other words people like the simple and direct route to a conclusion, rather than one which requires sustained attention, a sharp memory, and active deduction. So the wise speaker will construct his argument as a direct, not an indirect, proof. The aim should be to give strong, simple arguments, which offer clear, uncomplicated reasons, not elaborate and intricate analyses.