Understanding Primary Sources, Making Inferences, and Drawing Conclusions

Primary sources are often considered most trustworthy because they are closest to the original material and least likely to contain errors. However, readers must take a common sense approach to evaluating trustworthiness. For example, a single letter written by one biased witness of a historical event may not provide as much insight into what really happened as a secondary account by a historian who has considered the points of view of a dozen firsthand witnesses.

Tertiary sources are useful for readers attempting to gain a quick overview of understanding about a subject. They are also a good starting point for readers looking for keywords and subtopics to use for further research of a subject. However, they are not sufficiently detailed or credible to support an article, academic paper, or other document intended to add valuable analysis and commentary on a subject.

Evaluating Credibility

Not everything you read is equally trustworthy. Many sources contain mistakes, faulty reasoning, or deliberate misinformation designed to manipulate you. Effective readers seek out information from credible, or trustworthy, sources.

Sources and References

Credible texts are primary sources or secondary sources that refer to other trustworthy sources. If the author consults experts, they should be named, and their credentials should be explained. Authors should not attempt to hide where they got their information. Vague statements like “studies show” are not as trustworthy as statements that identify who completed a study.

Objectivity

Credible texts usually make an effort to be objective. They use clear, logical reasoning. They back arguments up with facts, expert opinions, or clear explanations. The assumptions behind the arguments do not contain obvious stereotypes.

Emotional arguments are acceptable in some argumentative writing, but they should not be manipulative. For example, photos of starving children may be acceptable for raising awareness of a famine, but they need to be respectful of both the victims and the audience—not just there for shock value.

Date of Publication

Information changes quickly in some fields, especially the sciences and technology. When researching a fast-changing topic, look for sources published in the last ten years.

Author Information

If an author and/or a respected organization take public credit for information, it is more likely to be reliable. Information published anonymously on the Internet may be suspicious because nobody is clearly responsible for mistakes. Authors with strong credentials such as university professors in a given field are more trustworthy than authors with no clear resume.

Publisher Information

Information published by the government, a university, a major national news organization, or another respected organization is often more credible. On the Internet, addresses ending in .edu or .gov may be more trustworthy than .com addresses. Publishers who stand to profit or otherwise benefit from the content of a text are always questionable.

Professionalism

Credible sources usually look professional and present information free of grammatical errors or major factual errors.

Making Inferences and Drawing Conclusions

In reading—and in life—people regularly make educated guesses based on limited information. When we use the information we have to figure out something nobody has told us directly, we are making an inference. People make inferences every day.

Example: You hear a loud thump. Then a pained voice says, “Honey, can you bring the first aid kit?”

From the information in this example, it is reasonable to infer that the speaker is hurt. The thumping noise, the pain in the speaker’s voice, and the request for a first aid kit all suggest this conclusion.

When you make inferences from reading, you use clues presented in the text to help you draw logical conclusions about what the author means. Before you can make an inference, you must read the text carefully and understand the explicit, or overt, meaning. Next, you must look for clues to any implied, or suggested, meanings behind the text. Finally, consider the clues in light of your prior knowledge and the author’s purpose, and draw a conclusion about the meaning.

As soon as Raizel entered the party, someone handed her a plate. She stared down at the hot dog unhappily.

“What?” asked an unfamiliar woman nearby with an edge to her voice. “You don’t eat dead animal?”

From the passage above, it would be reasonable to infer that the unfamiliar woman has a poor opinion of vegetarians. Several pieces of information suggest this: her combative tone, the edge in her voice, and the mocking question at the end.

When you draw inferences from a text, make sure your conclusion is truly indicated by the clues provided.

Author Glenda Davis had high hopes for her children’s book Basketball Days. But when the novel was released with a picture of a girl on the cover, boys refused to pick it up. The author reported this to her publisher, and the paperback edition was released with a new cover—this time featuring a dog and a basketball hoop. After that, many boys read the book. And Davis never heard anyone complain that the main character was a girl.

The text above implies that boys are reluctant to read books with a girl on the cover. A hasty reader might stop reading early and conclude that boys are reluctant to read about girls—but this inference is not suggested by the full text.

Let’s Review!

• Effective readers must consider the credibility of their sources.

• Primary sources are usually considered the most trustworthy.

• Readers must often make inferences about ideas that are implied but not explicitly stated in a text.