Summarizing an essay begins with identification of key points. What is the author's topic, and what does the author have to say about it? What, precisely, is the author's thesis? In some cases, the thesis in a piece of fiction or pure description is not openly stated. The author may simply imply through the use of examples and explanation what the reader should know or believe.

WARNING: in your own essays, don't attempt to use the implied thesis unless you're sure you can convey your meaning accurately and persuasively. It is effective in certain cases, but it exposes you to misinterpretation. Suppose your readers have knowledge or experience very different from your own, or drag in tangential issues, or are otherwise influenced NOT to reach--perhaps not even to understand--your conclusion? In some languages, writers use implied theses for reasons of politeness or because the structure of persuasive text in their language is less linear and direct than that of English. But, in English, and in western cultures, the implied thesis often is--and is seen to be--manipulative. Therefore, in academic writing at the university--and in writing done outside the university for an audience that might not reach the same conclusion you've reached--you will be safer to tell your readers openly what you want them to believe and why.

In addition to identifying the author's thesis and its logical support, a summary must focus on the points under discussion, and probably not on all the points. If you are writing a summary of a ten-page text, and you are allowed not more than 500 words for your summary, you must find the key points in the text and focus directly on the most important of them. Extraneous material may seem fine in casual conversations, but it will foul your writing and extend it beyond the 500 words.

Next, reread the author's conclusion; what happens in it? Does the author give you an overview? Does the author finally come to a conclusion that is the true thesis of the original essay? Once you have followed these steps and answered the questions, you are ready to write a summary.

Suppose you are asked to give your opinion of an essay you've summarized. Your summary tells you what's in the essay; your response gives your opinion, tells how you feel about the essay and why. The summary is a description; your response is an analysis. You feel a certain way about the essay; perhaps you agree or disagree with the thesis, or you're convinced that the author's proposition is illogical at the core, or that the author is willfully ignoring contrary evidence, or you believe that some of the evidence is misleading or doesn't really support it. You may even find that the author has missed some evidence supporting the thesis.

However you feel, you've arrived at a judgment after reading and thinking about the author's essay. Your task then, is to respond by using your judgment as your thesis and giving your evidence, factual and logical, to support your thesis. By following these steps, you can respond to other writing and critique it. You will know why you have a reasonable opinion, and you will explain why that opinion is valid to your readers.

Suppose, however, that want to agree with the author in your response. If you agree, you must cite reasons or evidence in addition to that given by the author. And you must show how the additional information supports or agrees with the author's argument. As one who agrees with the author, you need to explain why you agree with the author's point of view; you can't simply repeat what the author has said. If you were to do that, you would sound like a parrot, only imitating and mimicking the author. And you wouldn't explain why you agree with the author's perspective. Generally, it's easier to at least disagree partially, or provide a different point of view on the topic, than to wholly agree with the author.