APA Style (6th ed.)

To paraphrase is to communicate the author’s work in your own words and to acknowledge the source:

• Used to rewrite text in your own words
• Used to clarify meaning
• Used to shorten a longer statement, but keep the main ideas
• Giving credit to the original author of the idea

Elements of a good paraphrase:

• Change the structure of the original passage
• Change the words
• Give a citation / reference

To summarise is to describe broadly the findings of a study without directly quoting from it. Summarising involves repeating the main ideas of a passage in your own words.  A summary concentrates on the important points rather than the details.