Retelling is a valuable assessment tool for comprehension because it gives us insight in a child's comprehension process.  In addition, the practice of retelling improves comprehension, concept of story, critical thinking, and oral language development.  A way to guide children through retelling from a literal-level  comprehension to higher order thinking and interaction with the text is by using the following.  This is just a glimpse from a chapter devoted to this topic from The Power of Retelling: Developmental Steps for Building Comprehension (Cummins, 2000).

Predictions		I think this story is going to be about....
Vocabulary		I might use these words in the story...
Read the story		As the child reads, s(he) looks for affirmation of the predictions. 
                        A vocabulary discussion helps compare his/her words to the author.
Understandings		I noticed...
Interpretations		I wonder...
Connections		This reminds me of....because...
With the use of a "Go!Map" graphic organizer, children can use visual clues to help with the retelling process.
Retellings are done after a child has read the book several times and has completed the steps above.
1.  The beginning of the story is represented by a triangle because there are 3 things that we usually find out in the beginning of the story:
    the setting, the characters, the problem or goal.
2.  The middle of the story is represented by a rectangle.  This is where we usually find out the events that
    take place in order for the character(s) to solve the problem.  Summarizing to approximately 4 events is easy
    for children to do.
3.  The end is represented by a circle which illustrates the idea that "what goes around, comes around."  This means that
    we usually find out resolutions at the end of the story.