Re: Setup and Rule Diagrams

[Dave Killoran]

Setup and Rule Diagram Explanation

This is a Grouping: Partially Defined game.

Using WXYZ as the base is superior to using FGH since each of WXYZ must respond to at least one antibiotic, and the W X rule can easily be shown within the diagram. This leads to the following base diagram:

J93_Game_#4_setup_diagram 1.png

From the first two rules, because each organism responds to at least one of the antibiotics, but not all three antibiotics, each of the organisms responds to either one or two of the antibiotics.

The third rule establishes that either two of the organisms or three of the organisms must respond to F.

The fourth rule is diagrammed as:

• W X

This should also be shown within the diagram.

The fifth rule is diagrammed as:

• F G

From an inference standpoint, no organism can respond to both H and F because F brings along G, and thus F and H together means that an organism responds to all three antibiotics, a violation of the second rule. This deduction is the key to the game.

Via the contrapositive, if an organism does not respond to G, then it cannot respond to F. Consequently, if an organism does not respond to G, it must respond to H. If an organism does not respond to H, then it must respond to G (either it responds to G alone, or if it responds to F, then it also responds to G under the fifth rule).

Combining all of the above leads to the final diagram for the game:

J93_Game_#4_setup_diagram 2.png

[netherlands]

Hi there Powerscore,

I'm having the same problem with this game that I find myself having with many of them. I get stalled in the setup.

At first attempt, I simply applied the rules surface level: I came up with this diagram:

E _ _
_ _ _
_ _ E
Y Y E

Above the slots, F, G and H, respectively. Because two but not four could respond to F, I put an E in the top slot showing that it would be empty, and that F would either have 2 or 3 variables.

I also placed two columns of "E" for empty in the H first two H slots because the variables that match between F and G cannot be in H or would violate the rule stating that no organism can respond to all three antibiotics.

I quickly realized - (or at least felt) that trying to attack questions with this skim diagram was almost impossible. I realized that I needed to make some sub-diagrams, but couldn't determine what rule/trigger to base sub-diagrams off of. After staring at it for maybe 5-7 minutes I decided to make diagrams based off the 4th rule: W X.

This allowed me to make (3) sub diagrams that helped me. I couldn't find any online explanations for this game - and I guess my concern is that nothing about that rule jumped out to me at first showing that it should be the basis for sub-diagrams. Is this the way you would have recommended we solve this problem? And if so, what is a rule or observation you could share that could help me understand the decision to use the W X rule, in a way that doesn't seem so arbitrary.

Really appreciate your advice- because at this point I'm realizing that I need more direction/confidence in my setup more so than anything else.

Thank you!

[Dave Killoran]

Hi Netherlands,

I'm happy to help you out here. Before getting into this game much further, can you give me a sense of what preparation tools you have used so far? Books, courses, etc would be helpful for me to know, so I can gauge how to best frame my answer (it will also help me answer your other post about the Rule Substitution question in the O10 Archaeologist game). Or, if you are just studying old tests that would help to know too--I'm just looking for a reference point before I use some concept names you might not know.

I'm also getting the feeling from your posts that you are using the rules almost exclusively to dictate what setup to use. Is that a fair assessment, or is there some other analysis point(s) you use? Please let me know if you can.

Thanks!

[netherlands]

Hi there,

In answer to the first question, I've read and worked through the Logic Bibles, the Workbook and just had my first class two full length classes this past week. (I plan to take the June test.) So I guess it is safe to say at this point - that I recognize and can use Powerscore concepts at this point - but I still feel terribly bad at them - kind of like I'm still on training wheels ... and as if I will be using them for a while, which terrifies me.

This segues into your second question which is that I feel that I stall/panic in the initial setup which is where I spend the most time on games and lose most of my confidence while performing them if I can't immediately decide how to diagram them. I think that in an attempt to find "tricks" or shortcuts for myself, I immediately look for rules that will allow me to create sub-diagrams to make the game easier for me to manage. Besides that, I don't really think I'm using any other points of analysis - at least not "deep" ones - most of my knowledge for setup is really surface level, like knowing to use consecutive slots for basic linear, vs setting up columns and rows for ADV linear, knowing how to setup pure sequencing, and the proper notations to use for grouping games, etc.

Desperately searching for a way to finally narrow down my method of attack and get rid of this anxiety. If I could only find my way towards loving logic games - I could probably fall in love with the LSAT!

[Dave Killoran]

Great, that helps me understand your background knowledge. We've also got some similar LG themes over in your post http://forum.powerscore.com/lsat/viewto ... f=2&t=3430, so I'll focus more on the question originally posted here, and leave that one for the more in-depth LG discussion. One note though: the next several lessons your course are the foundational games pieces, so really focus on those and I think it will help with getting a hold on how to approach the setups.

With this June 1993 game, there are a few different things going on. First, note how many of the rules are about the organisms. In an uncertain base-choice situation, the more rules that revolve around one of the variable sets, the more likely that set is to be the best base. That's because we have more limitations with that group, and thus fewer choices for each space. that, combined with the intuitive aspect of giving antibiotics to the organisms, helps select the organisms as the base. If that thinking didn't jump out at you--scan the questions quickly. Notice how many answers start with an organisms, such as "W responds to..." In that scenario, having the organisms as a base will match the answer choices, making the game easier to solve.

If we select the antibiotics as the base, can we still do the game successfully? Yes, you can. The change I'd make to your diagram is to not have all four spaces going vertically, because what you've done is create a 4x3 grid, and now you have to track where each organisms is in the grid (hence the E after the two Ys, as I understand it). That adds a new layer consideration, and increases the complexity of the setup.

If you turn the game around and use W, X, Y, and Z as the base, then every organism as at least one and possibly two spaces above it, meaning you are only tracking between 4 and eight spaces (as opposed to 12 in your diagram). Y gets filled with F and G, and then you are done with Y, so now you are down to tracking 3-6 spaces, and the "F at least twice rule" is the one thing to really keep an eye on.

Finally, I wouldn't create templates for this game. The base setup is powerful enough that making templates costs more time than it saves.

Please let me know if that helps. Thanks!

[netherlands]

hi there,

thanks so much for your explanation! with that and going over several other games I can now see a couple of things that should have helped me create the easier version of the base the first time:

1) The intuitive aspect like you said of giving antibiotics to orgamisms (making the organisms the receiver/open slots) - not sure how I missed that, probably just through nervousness and not taking the time to absorb the stimulus.

2) Also the min and max restraints " each responds to at least one no org responds to all three" gives me a structural/numerical base to start with.

I think that under pressure those are the two things that I'd be able to spot.

The interesting thing is that here the Min/Max limitations helped me see that (our instructor pointed it out as a tip in class) but I cant completely just apply that mechanically bc there are some games where that doesn't always work.

In the June 1999 game #4, about researchers learning different languages, the researchers have MIN and MAX limitations - but then the languages are used as a base because the rules give exact numerical distributions for the languages. So I guess the point there is just that I can't apply things mechanically.

Thank you!

[kcw5sr]

I'm stuck. If anyone wants to help me with this game, I'd be very grateful

[Nikki Siclunov]

Hi kcw5sr,

This is indeed a tough game: you need to figure out which organisms respond to which antibiotics. Since each organism (WXYZ) responds to at least one antibiotic (FGH), it would be preferable to use the organisms as your base, establishing 4 groups with at least one and at most two variables per group (no organism responds to all three antibiotics).

How about inferences? Well, according to the fifth rule, any organism that responds to F also responds to G (F G). But no organism responds to all three antibiotics, so that organism cannot also respond to H! This establishes a key inference in this game (F H).

Your final setup should look like this:

Screen Shot 2015-09-27 at 8.30.34 PM.png

Hope this is a good place to start! Let me know if you have any other questions.

Thanks!

[biskam]

I want to make sure I have all the possibilities right here... is it possible for GH to be together?
I know that: FG can occur, H can occur, G can occur... but is it possible for GH to occur?

Also does anyone have any tips on how to get the ball rolling with inferences? Once I write down the rules and the obvious limitations for the rules, I get stuck. Are there certain things I should be looking at in order to find inferences?

Any help would be greatly appreciated.

[AthenaDalton]

Hi biskam,

GH could occur.

For this game, the key inferences that you need to get started have been sketched out in Nikki's diagram above. There really aren't a lot of inferences to be made up front, although as Dave mentioned templates can be helpful. The rule I would use to explore templates is the rule about F being used at least 2 times but not 4 times. The templates would involve placing F in W, X and Y in one template, placing F in Y and Z only in another, and finally placing F in X, Y and Z in the final template.

It can be tough to know when to stop looking for inferences and jump into answering the questions. I start by writing out the rules and any obvious inferences / contrapositives. Then, if a clear fork in the road appears (e.g., a rule like A can only go on day 3 or day 5), I sketch out what those scenarios looks like. I know that it's time to start answering questions after I've stared at the setup diagram / rules for a few seconds and haven't had any more ideas for linking rules together.

If in doubt, just jump into answering questions. If your diagram is inadequate, you will certainly realize it by the time you get to the second question.

Finally, it's ok if you don't make all of the inferences up front. It's common in games to find a difficult inference only when tackling one of the last questions in the set. As long as you find them in the end, you're ok!

Thanks for your question, and best of luck with the test next week!

Athena Dalton