When to use CLA Method on YES/NO Questions

[ria.patel21]

Hi MGMAT Staff,

I recently watched the YES/NO Testing lab. It was very helpful, but now I find myself struggling with knowing WHEN to use this method vs. when not to use this method. I know this strategy should be used as a "fall back," but when I see a yes/no question- my mind immediately thinks to "perform CLA."

Could you provide us with some question topics/examples that are easiest when using CLA and some that, while they may be yes/no questions, are easiest when using other solving methods.

For instance, in the 12th Edition OG #82 -
-this is a yes/no question
-topic: Divisibility/Primes/Multiples
-I initially used CLA and couldn't find the answer. But, when I went back and used another method (prime factorization), I found the answer right away. I want to avoid having to do this in the future because it wasted a few minutes of time trying to go from one process to the other.

Thus, what are some other types of problems where CLA will and will not be beneficial?

Thank you for your time and the many resources on this site!

Ria

[skyjarrett12]

Can someone fill me in on what CLA is or direct me to one of the Strategy Guides that I can read up on it?

[ria.patel21]

You can learn about it by watching the DS-Yes/No Testing Lab.

[tim]

i'll make you a deal: you help Sky by providing a brief description of CLA, and i'll help you with your questions. fair enough? :)

[ria.patel21]

Sky,

CLA is a method used for answering Yes/No Data Sufficiency problems. It stands for Criteria, List, Answer.

I made a flashcard that outlines how to use this method:

1. Read the question and gather what restrictions/limitations apply.
2. Generate a chart of CRITERIA for statement 1 + any restrictions from question, statement 2 + any restrictions from question, and both statements together + any restrictions from question.
3. Still working in the chart you made, LIST 5 possible values that meet that criteria. List integers in order starting from 0 if the criteria permits.

Two exceptions to this step:
A. If the question is asking about positive/negative, only list 3 values: negative, positive, and zero - or NPZ.
B. If the question is asking about fraction/integer, only list 3 values: fraction, integer, zero - or FIZ.

4. Finally, ANSWER is the last step. Answer the question by going through the list of values you made and marking each value with a YES or NO. If the values yield the same answer, meaning either that all values lead to YES when answering the original question or that all values lead to a NO when answering the original question, then that clue is sufficient. If some values yield yes and some values yield no, then that clue is not sufficient.

Hope this helps!

[tim]

thanks, Ria!

from what you describe, it sounds as if the heart of the CLA approach is testing numbers. i would say that this should ALWAYS be a backup method rather than your primary approach to answering a question. keep in mind that testing numbers is only definitive on a DS question if the statement is going to end up being insufficient AND the numbers you test end up demonstrating this by giving two different answers to the question at the top of the page. because of this, you should only use CLA if you don't have a more direct approach to verify the sufficiency of a statement OR if you are pretty sure the statement will be sufficient and are just looking for a couple of quick values to confirm your suspicion. as such, there are no specific topics i can point to where CLA will be more or less useful; however, you may find that certain types of questions are more appropriate for you to use CLA. this will come mainly from practice and careful observation of the problems you do..

[ria.patel21]

Awesome, thanks Tim!

[tim]

my pleasure!