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cubedemon6073
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05 Apr 2013, 6:32 pm

Let's say we have A and B.

In order to obtain B one must have A. This is considered a necessary condition.

If A guarantees B then A is sufficient to have B and this is considered a sufficient condition.

Am I correct so far? As an example let's try this.

Let's set A=obtaining a degree
Let's set B=obtaining a job in the field one obtained the degree in.

Certain college degrees are necessary to obtain a certain job but are not sufficient to obtain this same job.

Is this correct? Am I using the logic of necessary condition vs. sufficient condition correctly?



Last edited by cubedemon6073 on 05 Apr 2013, 7:15 pm, edited 1 time in total.

The_Walrus
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05 Apr 2013, 6:50 pm

Although I think you have omitted a word from your second sentence, yes, your logic seems good.



GGPViper
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05 Apr 2013, 6:51 pm

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The_Walrus
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05 Apr 2013, 6:54 pm

The above diagram is inaccurate. Sufficient conditions are not necessarily necessary. For example, there may be a university course where certain exam results are sufficient to gain entry, but mature students do not need these results.



cubedemon6073
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05 Apr 2013, 7:16 pm

The_Walrus wrote:
Although I think you have omitted a word from your second sentence, yes, your logic seems good.


I corrected it. I forgot to add the variable B. Sometimes I process and think through things faster than I type.



cubedemon6073
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05 Apr 2013, 7:18 pm

The_Walrus wrote:
The above diagram is inaccurate. Sufficient conditions are not necessarily necessary. For example, there may be a university course where certain exam results are sufficient to gain entry, but mature students do not need these results.


I agree with you Walrus. Not every member of sufficient is necessary and not every member of necessary is sufficient.



GGPViper
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05 Apr 2013, 7:26 pm

The_Walrus wrote:
The above diagram is inaccurate. Sufficient conditions are not necessarily necessary. For example, there may be a university course where certain exam results are sufficient to gain entry, but mature students do not need these results.

I admit that it was crude, but I believe it has some merit.

Fictional example:

You *can* pass a course by getting a grade of C or higher (but other factors will be considered). You *will*, however, pass a course by getting an A. Here, S (an A) is a subset of N (C or higher).

The "mature student" claim introduces an additional variable. If you focus solely on the students who do not meet the "mature" criteria, my logic holds...



GGPViper
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05 Apr 2013, 7:46 pm

GGPViper wrote:
The_Walrus wrote:
The above diagram is inaccurate. Sufficient conditions are not necessarily necessary. For example, there may be a university course where certain exam results are sufficient to gain entry, but mature students do not need these results.

I admit that it was crude, but I believe it has some merit.

Fictional example:

You *can* pass a course by getting a grade of C or higher (but other factors will be considered). You *will*, however, pass a course by getting an A. Here, S (an A) is a subset of N (C or higher).

The "mature student" claim introduces an additional variable. If you focus solely on the students who do not meet the "mature" criteria, my logic holds...

Ok, after doing some searches on the Internet, I believe I have identified the source of disagreement.

The "sufficiency" concept simply has different meanings.

Apparently, it is either:

1. A subset of necessity (B only if A + If A, then B)
2. An independent construct (If A, then B - Which does not exclude: If Some Non-A, then B)

I guess things get lost in translation...



ruveyn
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05 Apr 2013, 8:23 pm

If A implies B then B is a necessary condition for A and A is a sufficient condition for B.

That is all there is to it.

ruveyn



daydreamer84
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05 Apr 2013, 8:57 pm

ruveyn wrote:
If A implies B then B is a necessary condition for A and A is a sufficient condition for B.

That is all there is to it.

ruveyn


This is correct....a logically valid argument but I don't think getting a college degree to get a job fits this tautology.

If you get a X college degree it implies you can obtain Y job.

skipping over the first:

Getting X college degree is not a sufficient condition for getting Y job, unfortunately, Y job may also require some years of job experience or enough interpersonal skills for the manager to like you when he interviews you etc.

There are too many variables for you to say anything more than; for A you always need B. Not only B, no two way relationship but one thing that's absolutely necessary to get certain jobs is to have a certain degree. Not all jobs are like this but some are.



minervx
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05 Apr 2013, 9:55 pm

Wouldn't there essentially be four options:

1. neither
2. both
3 and 4. one or the other



naturalplastic
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06 Apr 2013, 7:52 am

So...

If A guarantees X, then A is a 'sufficient condition for X'.

But if X requires B, but B does not guarantee X, than B is a necessary conditon for X- but not a sufficient conditon for X.

Have I got it right?

So getting a law degree is a necessary condition for being a lawyer, but not a sufficient condition. But passing the Bar IS a sufficient condition of being a lawyer ( more or less).



daydreamer84
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06 Apr 2013, 2:06 pm

naturalplastic wrote:
So...

If A guarantees X, then A is a 'sufficient condition for X'.

But if X requires B, but B does not guarantee X, than B is a necessary conditon for X- but not a sufficient conditon for X.

Have I got it right?
So getting a law degree is a necessary condition for being a lawyer, but not a sufficient condition. But passing the Bar IS a sufficient condition of being a lawyer ( more or less).


Yeah, passing the bar but I'd say in terms of getting a college degree in order to get a job the best you can say is that A is a necessary but not sufficient condition for B. That's my experience of the job market anyway, unfortunately.