Preparing a good summary

Follow these steps:
  1. Read the material thoroughly. Look at visual cues such as headings, subheadings, and words in boldface and italic to identify the main ideas.
  2. Read the material again, now underlining or taking notes of the main points. Look for such pointers as first, second, and words that express causation (accordingly, therefore); words that express contrasts and comparisons (furthermore, however), and words that signal essentials (basically, principal). The first and last sentences of each paragraph are very often important.
  3. Organise the information into a draft summary. Use the language of the original, together with any necessary connective words or phrases of your own.
  4. Revise your draft and delete whatever you can. Do not get stuck on the "surface level" of the original text. For example, if there is a listing of details, see how many of your underlined points you might combine, condense, or eliminate. Check your draft against the original for accuracy.
  5. Put the revised version into your own words. Make sure your version eliminates unnecessary words, and compare it with the original for accuracy.
  6. Edit your summary, making sure that the summary is clear and concise. Keep the prospective readers in mind - they will probably never access the original material.
  7. Identify the source that you have summarised. Include bibliographic information in the title or a footnote or endnote.

There are several types of summaries:

An informative abstract
An informative abstract includes conclusions and indicates results or cause. When writing an informative abstract, think of it as a table of contents in sentence form. The table of contents of a report is, in effect, the final outline; it is easily fleshed out into an abstract.

All abstracts share these characteristics: (a) the writer never uses "I", passive voice is used instead; (b) footnotes are never used; (c) abbreviations must not be used, unless they are explained in the abstract.

An evaluative summary
When your write an evaluative summary, follow the same guidelines, but include your opinion of the material you are summarising. Blend your evaluation with the summary—don't summarise first and then provide a critique at the end. - Consider these questions: How carefully is the subject researched? Is the writer or speaker objective? Does the work achieve its goal? Is the material relevant to your readers? Is the material readable? What kind of vocabulary does the writer or speaker use? What visuals are included?

An executive summary
An executive summary is found at the beginning of a formal proposal or long report. It is usually one or two pages and condenses the most important points for a busy manager. It is self-contained and can stand on its own, like the report itself. An executive summary should begin with the purpose and scope of the report, relate the purpose to a key problem, give in non-technical language the criteria used to solve the problem, condense the findings, stress the conclusions, and provide recommendations.

Adapted from Kolin, P. Succesful Writing at Work. (Houghton-Mifflin).