Source: Buehl, D. (2009). Different Perspectives for Reading. Classroom Strategies for Interactive Learning (42-44). Newark, DE: International Reading Association.
The analogy chart can be a great way for teachers to help students connect something that is unfamiliar to something that they already know about. The book outlines 3 types of connections students bring to their comprehension of written texts: text-to-self, text-to-text, and text-to-world. Text-to-self is probably one of the most important one out of these three because it helps the student relate what happens in their lives to what the author says. The analogy chart provides a visual framework that students can use to compare and contrast new things to things they already know.
To use this strategy, a teacher must first determine what the students already know. This will help in relating the new material to somethings the students are familiar with. The book gives the example of how you can do an analogy chart on the concept of a colony in history class and how it can relate to a dependent child in a family. The teacher then introduces the analogy chart on a overhead screen and give a copy to the students so they can also fill it out with you. First, the teacher and the students brainstorm on the similarities between the two: for example, a colony and a dependent child both rely on a parent figure for their needs and they must follow rules or laws set by others. Next, the teacher and the students brainstorm on the differences between the two: for example a colony usually is separated geographically from the parent figure, while a child usually lives with the parent figure in a family group, and a colony is regarded as a negative system, while families are not. This is a very important step because the differences help students to not overgeneralize and it will help show that even though the two ideas are similar, they are still two different things. Then the teacher will discuss with the class categories that make up the basis for the comparison; for example, some of the relationships might be labeled as Dependence on others (both rely on the parent for protection and other needs). Afterwards the teacher will have the students write a summary about the similarities between the familiar and new concept using their analogy charts. I think analogy charts are a great way to get students to brainstorm and connect new ideas to familiar concepts so that they can better understand the new information.