Diagramming is an essential skill on the LSAT, but it’s also a bit like speaking a foreign language. At first you will feel awkward and clumsy and slow; then suddenly you’re spitting out full sentences and fully understanding the answers and you wonder why you ever had such a problem with it.
What is diagramming and why is it important on the LSAT?
Diagramming is a shorthand way of representing conditional statements (otherwise known as if-then statements). I don’t have enough space to fully get into the basics here, but if you’re studying for the LSAT and you’re not comfortable or familiar with conditional logic, you should do yourself a solid and look it up.
Diagramming crops up mainly on the Logical Reasoning sections and on Logic Games (for instance, Tanika is in every photo that Morlanda is in). It’s important to make note of and use conditional language because it can lead to additional deductions — and not always ones that are intuitive.
For those who have a basic familiarity with diagramming, here are a few diagramming tips to keep in mind:
Look for key words.
There are a whole bunch of key words that will help you identify and understand conditional statements — these are covered mainly in Lesson 1 of the Blueprint LSAT Prep curriculum, for any Blueprint students out there. You should always keep your eyes peeled for these words, and make sure you understand what they mean as well.
My example above (“Tanika is in every photo that Morlanda is in”) is a paraphrased version of an actual LSAT Logic Games rule, and students frequently diagram that rule incorrectly on the first try. “Every” introduces the sufficient condition, so what that rule is actually saying is that if Morlanda is in a photo, Tanika will be as well. As should be evident, noticing and understanding key words is an essential skill.
Look for similar terms.
When using the transitive property to draw additional conclusions from multiple conditional statements, before you worry about taking any contrapositives, start by looking for terms that the different statements have in common. From there, you should be able to determine which phrases (if any) require the contrapositive.
Similarly, when you’re actually diagramming the stimulus, try to diagram like terms in the same way. This requires some care, since you wouldn’t want to commit an equivocation fallacy by combining two terms that are actually different in an essential way. But if there are two phrases that refer to the same thing, diagramming them with the same abbreviation can help you draw additional conclusions.
Diagramming is tricky, but it becomes much easier with practice, and it’s an extremely powerful tool that should be a part of your arsenal on LSAT test day. Keep practicing diagramming now so that you can be as comfortable as possible with it on test day.