Hi, Melanie,
Welcome to our forums! Excellent question. There are several clues you can look at in a grouping game to determine which variables should be our base and which variables you should put into it.
- Start with the scenario paragraph. Describe the two possibilities and see how it sounds both ways. For instance:
- The technicians repair the machines.
The machines are repaired by the technicians.
Which way does this sound more fluid? The active construction in the first sentence beats the passive construction in the second sentence.
- Look at the rules. Which way are they worded?
- "Yolanda repairs..."
"Stacy does not repair..."
"Wim does not repair..."
In each of these it still seems as though we're figuring out what the technicians are doing. This is another good indicator you might want to use the technicians as the base here.
- Look to see whether there's a Global-List question. If there is, that's a dead giveaway for how to set the game up. Model your diagram after this question.
- Even if there's not a Global-List question, other questions will likely contain sufficient information to help you decide how to set things up. Consider the following question:
- "For exactly how many of the technicians is it possible to determine exactly which of the machines each repairs?"
To answer this question quickly and easily, we would want to look at the diagram and see which technicians repair exactly the same machines. This would be easier with technicians as the base of your diagram, so that's a good hint about how to set up the game.
If all else fails, remember that the game will work both ways. One way might be slightly weirder or harder than the other, but during your practice when you review, if you did a game in a more difficult/"backwards" way, look for clues or indicators that you could spot the next time to tell you how better to approach a similar game.
I hope this helps!
