The real art to research writing is using quotations and paraphrases from evidence effectively in order to support your point.  There are certain rules, dictated by the conventions of style you are following, such as the ones presented by APA or MLA.  There are also certain guidelines and suggestions that will cooperate with format conventions and also help you best utilize the material you are borrowing.

When all is said and done, the question of when to quote and when to paraphrase depends a great deal on the specific context of the writing and the effect you are trying to achieve.  Learning the best times to quote and paraphrase takes practice and experience.

In general, it is best to use a quote when:

• The exact words of your source are important for the point you are trying to make.  This is especially true if you are quoting technical language, terms, or very specific word choices.
• You want to highlight your agreement with the author’s words.  If you agree with the point the author of the evidence makes and you like their exact words, use them as a quote.
• You want to highlight your disagreement with the author’s words.  In other words, you may sometimes want to use a direct quote to indicate exactly what it is you disagree about.  This might be particularly true when you are considering the antithetical positions in your research writing projects.

In general, it is best to paraphrase when:

• There is no good reason to use a quote to refer to your evidence.  If the author’s exact words are not especially important to the point you are trying to make, you are usually better off paraphrasing the evidence.
• You are trying to explain a particular a piece of evidence in order to explain or interpret it in more detail.  This might be particularly true in writing projects like critiques.
• You need to balance a direct quote in your writing.  You need to be careful about directly quoting your research too much because it can sometimes make for awkward and difficult-to-read prose.  So, one of the reasons to use a paraphrase instead of a quote is to create balance within your writing.