Diagram

[janelso3]

Hi,
Could someone please help with the setup for this game? I initially set it up as an advanced binary grouping game with all the candidates listed in the In and Out columns. I grouped them into two groups using a dashed horizontal line and labeled them "e" (experienced) and "i" (inexperienced). The problem is we have another TYPE of subgroup, geo and radio. How do we deal with this in our diagram?
Thanks,
Jeff.

[dan]

Hey Jeff. The reason the Logic Chain diagram isn't working for you is that this game doesn't give us any conditional constraints. At first, it seems as if it'll be an advanced binary grouping game with two subcategories, but when we get to the rules we see that it's actually not going to be a game with a bunch of arrows symbolizing conditionals. Also, we actually get a cross of categories, which is an unusual wrinkle. It's clear our standard approach for binary grouping isn't a match for this particular game.

In fact, this game doesn't really have any obvious inferences at all. The real challenge comes in organizing which categories each letter falls under. I'll recommend a four x four grid with the titles E and I along the top as the column headers and the titles G and R along the side as the row headers. Try drawing it out now. You should have four distinct cells.

Imagine we've drawn the four x four picture. The upper left cell would be astronauts who are both experienced and geologists (F), the upper right cell would be those who are inexperienced and geologists (M, P, T), and so on. Go ahead and fill in the remaining astronauts according to the rules given.

The key to this game is realizing, once you've got the grid drawn, that exactly two from each row and exactly two from each column must be selected. Put 2's next to each row and column to remind yourself that you must have exactly 2 E's, 2 I's, 2 G's, and 2 R's. For example, I know I could NOT select F, J, and L, because that gives me three astronauts who are experienced (if you've got your grid drawn, you'll see it more easily).

This provides a clean organization. If we also notate that we need to have either P or L or both:

P/L/both

...we should be all set with the setup.

This is certainly not a typical binary grouping game, but with this grid-like organization of the letters it turns into a pretty straightforward game.

Remember, flexibility is the key! Hope this helps.

dan

[janelso3]

Hi Dan,
That is very helpful. I later realized that this wouldn't work with the logic chain setup since it lacks conditional constraints but still had difficulty keeping track of which two groups (geologists/radiologists; experienced/inexperienced) each candidate was in. The game is easy now.

Thanks,
Jeff

[dan]

Great. Glad that helped, and thanks for the post.

dan

[Nina]

still cannot quite envisage the diagram. Can someone please give an example diagram?

Thanks a lot!

[timsportschuetz]

Another method that works great with games of this particular type!

[christine.defenbaugh]

Thanks for the grid diagram timsportschuetz!

Here's the complete diagram. This takes dan's explanation above just one step further.

Because you know you have to have 2 Es, there are two ways to do this. You have use two Rs (from J-K-L), or you can use 1 R and 1 G (F). If you use two Rs, you are then forced to use two Gs for the inexperienced row. If, on the other hand, you use 1 R and 1 G (F), then you must use 1 R (N) and 1 G for the inexperienced.

These two frames can help you quickly see the relationships!



I hope this helps!

[jerichodeep]

See from Tim's charter, I think F and N must be selected together. i.e., F <--> N