Comparing two things well means saying what they share as clearly as how they differ, and students almost always find the differences easier. These organizers separate the two jobs. Alongside the columns for each subject there is dedicated space for similarities, and — on the matrix versions — a left-hand column for naming the feature being compared, which is the step that turns a scattered list into an actual comparison. One is bigger and one is smaller is not a comparison until you name size as the criterion.
Two formats: a three-part chart with a column for each subject and a shared similarities panel, and a comparison matrix with rows for named features and a column per subject. The matrix versions include a blank feature column so you choose the criteria. All areas are ruled for writing. Black and white, one organizer per US Letter page.
A Venn diagram is more visual and better for younger students or a quick sort. These charts hold more text and, in the matrix form, force you to name the criteria you are comparing on — which produces sharper comparisons but takes longer. For a piece of writing that will follow, the chart is usually the better planning tool.
What is a comparison criterion?
The specific feature you are comparing both subjects on — habitat, cost, tone, size, method. Naming criteria in the left column prevents the common problem of listing a fact about one subject with no matching fact about the other, which reads as two descriptions rather than one comparison.
How many features should I compare?
Three to five is usually enough for a paragraph or two of writing. More than that and students produce a table that is complete but has no argument in it. Choosing which criteria matter is part of the thinking, so it is worth resisting the urge to fill every row.
Can this be used for texts as well as objects?
Yes — two versions of a folk tale, two accounts of the same event, a book and its film adaptation. The matrix format handles these particularly well because the criteria can be things like point of view or ending rather than physical properties.