When to diagram in Logical Reasoning questions

Diagramming is an invaluable skill for LSAT test-takers. For Logic Games in particular, getting a good score is highly commensurate to your ability to quickly diagram information in a manner that clear, concise, and easy to refer to as you’re working through the test questions. Diagramming is also an extremely helpful tool in figuring out some of the tougher questions in Logical Reasoning. This blog post covers some tips to help you decide which questions you should diagram and some basic tips to keep you on track. 

When NOT to diagram

In general, less is more when it comes to diagramming in the LR section. Getting caught up in trying to crack each question the way you would in Logic Games would make it almost impossible to finish the section on time. Remember that for each section of the LSAT you have 35 minutes, and the LR sections tend to have between 25 and 26 questions. That means that you have less than a minute per question to read the stimulus, understand the argument, and pick the correct answer choice. For most questions, it is usually a better use of your time to identify the different parts of the stimulus, understand and pick apart the argument, and try to reach the answer that way. While there is no hard rule, diagramming more than six or seven questions per LR section could put you in a time crunch.

With that said, here are some scenarios when diagramming can help you figure out some of those tougher questions:

1.) When you have a tough parallel reasoning or parallel flaw question

Though diagrams are not necessary to crack every parallel reasoning question, a quick sketch of what the stimulus is saying can help you keep track of argument structure and compare it to the answer choices.

For these questions, the question stem may look like the following: 

1. Which one of the following uses flawed reasoning that most closely resembles the flawed reasoning used in the argument above?
2. Which one of the following exhibits both of the logical flaws exhibited by the argument above? 
3. “Which one of the following is most closely parallel in its reasoning to the reasoning in the argument above?” 
4. “The structure of the reasoning in the argument above is most parallel to that in which one of the following?” 
   
   

If time allows, making a quick diagram of the stimulus can help you keep the information clear and quickly match it to the answer choices.

2.) When you don’t understand what the stimulus is talking about

LSAT test makers will often use unfamiliar terms or subjects to confuse test takers and make an argument look harder than it is. Regardless of whether the stimulus is about science, philosophy, medicine, or any other topic you might not know too much about, it’s important to not get distracted by the actual content but rather focus on the structure of the argument! 

Let’s say you encounter a sentence in the stimulus that says: “All semiconductor power devices require a gate signal to initiate current conduction.” Without knowing even what a semiconductor is, we can substitute “semiconductor power devices” as SPD and “requires a gate signal to initiate current conduction” as GST, to keep it short. Translated to conditional logic short form, we can turn that convoluted sentence into:

SPD ? GST

That simply says if you have a semiconductor power device (SPD), then it will require a gate signal to initiate current conduction. What matters here isn’t your knowledge electricity and conduction, but rather your ability to understand the relationships in the argument.

3.) When you're Coming back to a previously skipped question

Given that you have under a minute per question when tackling the LSAT, it is important to not get hung up on any single question for too long. If a question is taking too long to answer or is a type of question that you typically have a hard time with, it is often best to eliminate some answer choices (if any), flag it, and move on. When you finish going through the rest of the section, come back to those tougher questions and, if time allows, use a diagram to make sense of the different pieces of the argument.

Remember that as with all LSAT tips, the best test-taking strategies ultimately come down to each individual test taker. Finding the best way to tackle the LSAT comes with practice (lots of it!) and getting comfortable with the test in a way that makes the most sense to you!