OK, working on PT 9 - Section 2 - Question 23:

This one was tough! I know there are many ways to do this one, so here's my attempt at explaining what's going on:

The **premises** can be translated as:

"Either you're rich or poor"

/R (---) P

"You are either honest or dishonest"

/H (---) D

"All poor farmers are honest"

P ---> H

The **conclusion** can be translated as:

"All rich farmers are dishonest"

R ---> D

The setup should look like this:

/R (---) P

/H (---) D

P ---> H

_________

R ---> D

The first thing to do is to secure the the *sufficient* clause of the conclusion:

R

The only thing that R can link up with is /P, so next link up /P.

R ---> /P

There really isn't anything else that we can do with /P, which is our hint that this is where the missing premise starts. The only other approach is working backwards from the necessary clause.

If we know that the *necessary* clause of the conclusion is D, let's add that, with some space between, to what we already have.

R ---> /P ---> ? ---> D

The only thing that can link up with D in our premise set is:

/H (---) D

so let's fill in the blank with /H.

R ---> /P ---> /H ---> D

From here, we have reached the conclusion and we used a new connection that wasn't in our premise set, /P ---> /H.

Unfortunately, this exact statement isn't in the answer set. But we can take the contrapositive of it, which is in the solution set: H ---> P.

Some of the difficulties of this one are: 1) Choosing which letters to represent the statements. I was tempted to use /R to represent "Poor" and /H to represent dishonest, which highlights the mutual exclusivity. However, it became too confusing for me, so I ended up sticking with the terms used in the stimulus. The second difficulty was 2) realizing that the missing sufficient assumption was smack-dab in the middle of the expanded conclusion and realizing that I had to work "backwards" from the necessary condition.

This problem was deceptively difficult for me for those two reasons. Hopefully this is a help for someone out there.

pp

#help

Had it down to A and C. A was more obviously the correct AC of the two, so I went with that one. I'm not totally convinced that C is absolutely wrong. Let's imagine that we have a large set, say 10,000 beliefs. The set is 99.9999% accurate, only 1 wrong belief. In this case, the statistician is correct that our belief set is smaller after rejecting our 1 belief with adequate evidence but our belief still consists of "many beliefs in order to survive."

It seems that there are at lest two levels of flaw in the question stimulus. The first level is in the argument about having correct beliefs to survive. AC A points this out. The second level concerns whether there is a counterexample to the argument about having correct beliefs to survive. It seems that AC C points this out.

pp

#help

I had it down to B and C. I understand why B is the correct answer, but I'm not fully understanding why C is incorrect.

I'm not totally sold on the argument that because he "based" his decision on the report, that the report was "the only direct evidence that needed to be considered." My understanding of using something that a base of a report is that whatever is in question is the foundation of how one makes the argument or document, but the stimulus is silent on whether or not the commissioner used any other resources or more importantly whether the commissioner thought the neighborhood report was the only evidence "needed to be considered" to make his decision. Whether or not the commissioner did use any other resources actually seems a little tangential here.

Any helpful thoughts on this one?

Thanks,

pp