Answer:
When source material is too long and detailed to be quoted
Step-by-step explanation:
When a writer paraphrases, he or she rewrites the information in his or her own words instead of quoting directly, trying to maintain the same level of details than the original text.
When summarizing, the writer captures the essential idea of a passage in a more concise manner. Thus, it is useful when working with long texts in which details are not so important to the overall idea.