Summarizing is an important skill and one effective readers use all the time. When we summarize, we 'get the gist' of the what we are reading. But summarizing can be a very hard skill to learn and to teach.
Summaries differ from retellings. Unlike retellings that include everything that happens in a story, a summary requires the reader to be selective, to include only the most important information.
When summarizing fiction, ask students to tell just the names of the characters, the setting where the story takes place, the problem facing the characters, the important events that happen to the characters and how the problem is eventually resolved.
Summarizing nonfiction is different. We read nonfiction to learn new things. So when summarizing nonfiction, ask students to tell what new things they learned! Who, what, when, where, why and how? What surprised them? What do they still wonder about?
Whether reading for pleasure or to learn new things, summarizing is a key strategy for students to use to comprehend text.