LR Diagramming Tips

Comments

• chocolatesprinkles-1 Alum Member

  July 2022 22 karma

  ^^ me too! would love some advice
• 4 Likes

  AlexLSAT. Alum Member

  July 2022 802 karma

  In my opinion, diagramming is important to learn the foundations of logic, but what is more important is being able to naturally see logical relationships and be able to pick out correct answer choices without diagramming at all. This process takes up a lot of time, and, on an already very time restricted test, it can mean the difference in you not being able to get to another question. So, in my opinion, it should be used as a fallback method to your intuition once you have a foundation and have practiced questions that have heavy logic.

  To answer your question specifically, I found that this worked for me:
  1. Memorize sufficient/necessary indicators and rules
  2. Memorize and be able to recognize valid and invalid argument forms
  3. Drill question types that tend to have heavy logical relationships in the stimulus (MBT) and watch the videos after for how J.Y. diagrams each question.

  Again, the goal here is that you don't have to diagram at all and instead can intuitively see the logic in the stimulus and the correct answer, and this improved for me after practicing enough of the method I used above. You got this!
• 2 Likes

  Claudia77 Member

  July 2022 106 karma

  What question type(s) are you trying to diagram? Personally, I mostly only diagram parallel reasoning questions because I find that diagramming generally isn't worth the time on other question types. For diagramming parallel q's, making an accurate diagram of the stimulus is key. To do this, you have to be able to identify the premises+conclusion and represent them symbolically.

  It's easiest to show with an example - I'm going to use question 14 from PT 6 section 3.

  The stimulus (paraphrased) states that during a recession, overall demand is low. If demand is low, so are interest rates. Therefore, if interest rates aren't low, the economy is not in a recession.
  I would diagram this stimulus in the following way:

  R --> DL (recession, then demand is low)
  DL --> IL (demand is low, then interest rates are low)
  IL --> R (interest rates not low, then no recession)

  After you've diagrammed the stimulus, it's a matter of finding an ac that mirrors the structure of the stimulus argument.
  In the above example, I will be looking for an ac where the antecedent of the first premise is the negated consequent of the conclusion, and the consequent of the second premise is the negated antecedent of the conclusion.

  Answer choice B states that if the fish is ready, it is cooked. If the fish is cooked, it will be white. Therefore, if the fish is not white, it is not ready.
  This yields the following diagram:

  R --> C (ready, then cooked)
  C --> W (cooked, then white)
  W --> R (not white, then not ready)

  Comparing this diagram to the stimulus diagram, it's clear that they mirror each other; they have the exact same structure. B is the correct answer. The other answers won't yield diagrams that exactly match the stimulus like this. If you have specific questions re: diagramming parallel q's I can elaborate more.
• 2 Likes

  mikaylag-1 Member

  July 2022 62 karma

  Thank you! Both of those explanations were very helpful!