Principles for LSAT LG Diagramming
I want to share some LSAT Logic Games principles with you that were a lightbulb moment for one of my tutoring students recently.
This student had been struggling with the diagramming aspect of logic games and was mostly getting paralyzed trying to figure out what the best way to diagram each rule was. After working through a couple of games, we created a master list of high-level principles that could help him (and YOU) know that his diagrams were always setting himself up for success in the game.
These principles aren’t a list of how to diagram rules like “G and H must be in a group together,” etc. Instead, it’s a list of principles that more generally apply to ALL of your diagrams.
I invite you to grab some of your recent scratch work for a games section. Compare your diagrams with the principles below, considering where you may need to give more attention.
Simply put, make sure your diagram matches exactly what the rule means. Of course, that is easier said than done, especially for long, convoluted rules. But it can be easy to make mistakes even for more straightforward rules as well. Consider a rule that states that “H cannot appear before L.”
Does that mean that H is after L? For many games, it will. But for some games, you’ll need to keep open the possibility that H and L appear together at the same time.
If you’re normally pretty good with games, but one particular game just completely threw you off, see if you might have misinterpreted a rule. Then work to prevent that in the future by creating a habit of double-checking whatever it is that you tend to misread or misdiagram.
To the extent possible (without taking lots of time), strive for simplicity rather than clutter in your diagrams.
Let’s say you have a game asking you to determine the order that both puppies and kittens were sold, Monday through Wednesday. You could do this:
___ ___ | ___ ___ | ___ ___
Two blanks for Monday (puppy first, then kitten), then two blanks for Tuesday (puppy first, then kitten), and finally two lines for Wednesday (again, puppy first, then kitten).
But it would probably be easier to visualize if you did this:
___ ___ ___
___ ___ ___
Puppies in the top row. Kittens on the bottom. Monday in the first column, Tuesday in the middle, and Wednesday in the last column.
The goal here is to make sure your diagram is helping you think through the questions more quickly and painlessly.
Ideally, you should be consistent with how you diagram a common rule type across multiple games, but at the very least, make sure you are consistent within each individual game.
For example, if you have rules like “H and G go together” and “L and Y go together”, make sure you diagram them the same way, whether that’s putting them in a box together or writing something like H=G.
This consistency will make it easier for you to remember what your diagram means and will help you more easily apply your diagram in the questions.
Nearly all rules can be represented visually somehow, even if it can be difficult to see how to at first.
And when you do create that visual interpretation of the rule, make sure to use vertical and horizontal space meaningfully. That is, if you have a game about floors in an apartment, organize your sketch vertically to mimic the apartment building itself. If you have a game about scheduling people into days of the week, organize your sketch horizontally to mimic a calendar.
This applies to rules as well. Let’s say your main sketch uses columns to represent three groups. If you have a rule like “S and T must be in the same group,” then write that rule out vertically in a column as well. It will be easier to visualize dropping the two entities together into one of the columns for the groups.
Exception: Some rules are really tough to figure out how to represent visually. Don’t spend too much time trying to figure out the “perfect” way to sketch the rule visually if it might make more sense to just use words. Many students find that writing out “no consecutive puppies” is an easier way to represent a rule preventing a puppy from occurring next to another puppy, for example. Sure, you could represent it visually, but don’t stress about it if you can’t figure out how.
Mostly, the caveat above is to prevent you from falling into the temptation of saying “oh, I’ll just remember that rule.” Don’t trust your memory, and don’t overburden your working memory by forcing yourself to keep thinking about a rule you decided not to write down.
I’ve noticed that when a student decides to “just remember” a rule instead of writing it down, the rule inevitably gets forgotten at some point. So set yourself up for success and make sure to write it down somehow.
Be especially careful about rules that might be hidden in the set up paragraph. These could be rules about how many people go in each group, whether entities can be repeated, etc. It’s so easy to not even realize that these are actually rules, but they absolutely need to get represented in your diagram somewhere.
The whole reason we make diagrams for the logic games section is to USE them when answering the questions. In order to do that, we need to make sure we are diagramming the rules in a way that we’ll actually pay attention to them whenever they become relevant.
If you ever find yourself ignoring a rule, ask yourself what you can do to make your diagram for that rule more noticeable. It might be something as simple as circling or starring the rule. Or you may need to rethink where you are writing the rule or how you are writing it.
Take a look at your diagrams for a few games you’ve done recently. How well do your diagrams align with the principles outlined here? What do you need to work on in your diagrams to make them more helpful?
Reach out if you need support or advice. I’m always happy to help.