A student writes me for advice about writing summaries. I thought readers of this blog might also find the answer useful. The difficulty, of course, is to provide a more concise version of something you have read without leaving anything important out. What are some strategies that might help you do this?

First, keep in mind that you always have to summarize from some perspective, and that perspective will necessarily be, in part, your own. Be aware of why you are reading this text, what is it that makes it interesting to you. And then make sure your summary includes the things that serve your interests in the text. For example, I often find myself summarizing Karl Weick’s analysis of the Mann Gulch disaster, which I think is flawed in a number of ways. So my summary always includes the things I think he gets wrong. Out of fairness, however, I also usually include the things he gets right, the things I agree with him about. You might also think about what parts of the text satisfied your curiosity. These things should also be in your summary, as should the parts that surprised or even outraged you. In other words, summarize the interesting claims in the text.

There is, of course, no “complete” summary of a text that isn’t just a perfect copy of that text. In order to make your summary useful, you will always leave something out. The trick is to leave the right things out for the right reasons, and that’s where your own interest in the text is so important. You have to have a good sense of why you are reading this text or, perhaps, what interest the reader of your summary will have in the source. Sometimes you are writing a summary just for yourself. But sometimes you are writing it to spare someone else the trouble of reading a longer document. There is no way to know how to do this without knowing something about your reader.

More practically, you might begin by making a “key sentence outline” of the paper or document you are summarizing. For each paragraph, try to find the one sentence that states its main point. That will give a list of 40-60 sentences for a standard research paper, which is probably a longer summary than you want. But one of those sentences will, ideally, state the overall conclusion of the paper. Your task now is to find the most important supporting arguments for that conclusion among the rest of the sentences in your outline.

Every time you make a summary, set some constraints on the task: How long should it be? How much time are you going to give yourself to do it? And make sure you have some purpose in mind, a focus: are you interested in the methods used in the study or the conclusion it reaches? Or are you interested in the recommendations the author makes for practice? Remember to summarize the paper on your terms, not necessarily those of the author you are summarizing. The summary should be useful to you and your readers, and while it should of course be “fair” to the original (i.e., it should represent the contents accurately), it doesn’t have to say everything the original says. You have to make some choices.

At the end of the day, when evaluating the summary try to identify the “trouble” it actually does spare you and/or your reader. And at what cost. A good summary will allow your reader (who may be your future self trying to remember what the document says) to make do without reading the document (at all or again). They will become more efficiently informed about certain things. But what will not reading the whole source document cost? What will the reader of your summary remain ignorant of because you left it out? Is that information important?