Discovering Ideas Handbook

 2.4    Support Your Claims

People will usually take your word for certain kinds of claims.  These include claims about events that you have personally participated in or observed.  For example, when you tell me when and where you were born, what your name is, or what you do for a living, I will usually believe you unless I have some reason to doubt you word.  Likewise, if we  believe people are knowledgeable about a subject, we will tend to believe what they say about that subject--to a point.  And, of course, we tend to believe other people when they tell us things that we already believe.  "Common knowledge" consists of a broad range of claims that most people believe as a matter of course, just because they live in the same culture.  (Common knowledge might not be the same for people from a different culture, which is why it can often be harder to communicate clearly with people from another culture.)

When you write an essay, many of the claims you make will be drawn from our cultural common knowledge, which you share with your readers.  But if your entire essay consists of common knowledge, it won't be a very interesting essay.  You'll just be telling us what we already know, stating the obvious.  Your thesis statement would be neither controversial nor informative (  So if your essay is going to be interesting, if it is going to tell us something we don't already know, most of what you say will be claims that we are unsure about.  Sometimes they are the kind of claims that we will accept on your authority--for example, a personal experience that illustrates your point.  But unless your essay is entirely about your own experience, we probably won't accept your word for everything.  (You can, of course, write a good essay just from your personal experience.  But you probably can't write three.  And you probably can't write one on any topic.  It would require a topic that you have significant experience with.)  So the major factor, often the major factor, determining whether your readers believe what you claim will be the quality of your supporting evidence.

Evidence is information that answers the question "How do you know?" of a claim you have made.  Please take that question very literally.  It is often hard to tell the difference at first between telling readers  what you know and telling them how you know it.   But to become an effective writer, in almost any context, you need to be able to ask this question repeatedly and test the answers you give for effectiveness.

2.4.1    Discover what claims in your essay need supporting evidence.

2.4.2    For every claim that readers might doubt, tell your readers how you know the claim is true.

2.4.3    Explain your sources and cite them where necessary.

2.4.4    Apply the tests of evidence to your supporting material.    Source Tests    Direct Tests

2.4.1    Discover what claims in your essay need supporting evidence.

You may need to point out in writing your essay that China is the largest nation in the world, in population, or that most Americans watch television or that Barak Obama was elected president in 2012.  Claims like these draw on common knowledge.  You can assume that your readers will recognize the truth of such claims without any further evidence. You can also assume that readers will accept claims about your own personal experience--assuming they sound reasonable--without further evidence.  But when you make a claim that is not common knowledge, then you need to support it.  

In reviewing your essay, keep in mind that not everyone knows everything you know.  If you are writing to a general college-level audience you need to assume that many readers will not know detailed information about most subjects.  

2.4.2    For every claim that readers might doubt, tell your readers how you know the claim is true.

Most of the words in a good essay will be devoted to answering the question "How do you know?"  When revising your essay, take that question very literally.  If you do in fact believe that a claim you are making in your essay is true, let your readers know what you saw, read, or heard that convinced you it was true.  In many cases, of course, you may not be able to answer that question without doing further research, because you may not remember how you learned something.  That means that you will have to, in effect, learn it again for your essay.

Note that the standard here is that you should support every claim that readers might doubt.  Don't fall into the trap of assuming that everyone knows what you do.  If a reasonable person could question your claim, you should tell us how you know it's true.  Even readers who tend to agree with you already or know most of what you're saying will find that your essay more strongly reinforces their existing beliefs if you support your claims with good evidence.

There are several ways of telling readers how you know.  In some cases, you have learned that your claim is true through personal experience.  Tell your readers about the experience, so they can see how you learned what you know.  If your description of a child with Attention Deficit Disorder is based on your observation of your younger brother, who was diagnosed with the disorder, then tell us that.  And describe what you observed.  If you conceal your experience and just give us your conclusions we have no reason to accept the conclusions.

The experience you relate doesn't have to be your own direct experience, of course.  You may have read about an example in a book or even seen a documentary on television that illustrated the point you are making.  That's fine.  Tell your readers whose experience illustrates your point and how you found out about it.

Often experience and examples aren't enough because you are making claims about most people or a large number of people.  In that case, you need to show your readers not that the claim you make was true once but that it is true often.  How do we know that most students who attended private schools in high school had an experience like yours?  How do we know that most kindergarten teachers use techniques like the ones you observed in Mrs.  Andersen?  To generalize beyond examples like this usually requires either statistical evidence or the testimony of experts.

2.4.3    Explain your sources and cite them where necessary.

In order to tell us how you know something, you need to tell us where the information came from.  If you personally observed the case you are telling us about, you need to tell us that you observed it, and when and where.  If you read about it, you need to tell us where you read about it.  If you are accepting the testimony of an expert, you need to tell us who the expert is and why she is an expert in this field.  The specific identity (name, position) and qualifications of your sources are part of the answer to the question "How do you know?"  You need to give your readers that information.  

Keep in mind that it is the person, the individual human being, who wrote an article or expressed an idea who brings authority to the claim.  Sometimes that authority may be reinforced by the publication in which the claim appeared.  Sometimes not.  But when you quote or paraphrase a source you are quoting or paraphrasing the author, not the magazine or journal.

So if you were introducing a source on the effects of progressive education, which of the following would sound more persuasive:

The last example is the most persuasive because most specific.  The name and qualifications of the source are the most important information in establishing the credibility of your evidence.  Never omit them.  Usually the best way to introduce a quotation is to make the name of the person you are quoting the subject of your sentence.

Of course, sometimes the source will not be an individual author but several people or an agency or group.  Always report the authorship as it is presented on the title page of the work.

Whenever you got your information from a published or broadcast source, whether you are quoting it directly or not, you need to list the source in your list of works cited and cite it correctly in the text.  The detailed rules for doing that in MLA format are in K&M 33a.

2.4.4    Apply the tests of evidence to your supporting material.

You have evidence that you plan to use in your essay.  The key question for you, because it will be a key question for your readers, is whether the evidence is true, whether you can trust it.  How do you tell?

Unless you are reporting your own personal experience directly to us, your evidence comes from somebody else.  If you use the word of some other person or group to answer the question "How do you know?" it just moves the question back a step: How do they know?  Even if you you understand them, and they were telling the truth as they saw it, they may have been just plain wrong. If you really care about the truth of what you are reporting, then you have to have some way of checking the reliability of your sources. 

In reviewing one another's evidence, you can use a few tests that are widely used to evaluate evidence and sources.  Not all of these tests are relevant to all evidence, but one or more of them will apply to almost all evidence.  

They fall into two broad categories: source tests, tests that apply to the credibility of the source of the evidence; and direct tests, tests of the evidence itself.    Source Tests

  1. Specific Reference to Source:  Does the writer indicate the particular individual or group making the statements used for evidence? Does the writer tell you enough about the source that you could easily find it yourself?

  2. Qualifications of the Source: Does the writer give you reason to believe that the source is competent and well informed in the area in question?

  3. Bias of the Source: Even if expert, is the source likely to be biased on the question? Could we easily predict the source’s position merely from a knowledge of his job, her political party, or organizations she works for?

  4. Factual Support: Does the source offer factual support for the position taken or simply state conclusions?

  5.    Direct Tests

  1. Recency: Is the evidence too old to be of current relevance to the issue? Would the source have had knowledge of recent developments or discoveries that might have bearing on the issue?

  2.  Sufficiency: Is their enough evidence to justify all of the claims being made from it?

  3. Logical Relevance: Does the claim made in the evidence provide a premise which logically justifies the conclusion offered?  Can you reasonably draw the conclusion being urged based on what the evidence says?

  4. Internal Consistency: Does this source make claims that are contradicted by other claims from the same source?

  5. External Consistency: Are the claims made by this source consistent with general knowledge and other evidence? If not, does the writer account for this discrepancy?


2.5    Use Specifics and Examples

Copyright © 2000 by John Tagg

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