NA help please

[yousefhosny.hm]

The argument: Studies have shown that private tutoring is an effective approach for learning a second language. Thus private tutoring is a fun way to learn a second language.

Answers:

"Anything that is an effective approach for accomplishing a gaol is also a fun approach for accomplishing that goal."

Negated: Nothing that is an effective approach for accomplishing a gaol is also a fun approach for accomplishing that goal.

"Some activities that are effective are fun"

Negated: No activity that is effective is fun

I don't get how both these answers are saying different things. I think they are both NA, but apparently the first answer is not a NA.

How is the first answer not NA? And is there a difference between these two answers in what they are saying?

[ohthatpatrick]

Negating something is taking the minimum contradiction of a statement.

Negating is like hearing something and saying "Nuh-uh!"

PERSON 1: All people in prison are guilty of their crimes.
PERSON 2: Nuh-uh!

What is person 2 committing to? Does she now have to defend the idea that "NO people in prison are guilty of their crimes"?

Of course not. She's just attacking the idea of "All". She thinks that there is probably at least one person in prison who's innocent.

Contradicting "all" means "not all". "Not all" means "at least one exception".

PERSON 1: Some people in prison are innocent of their crimes.
PERSON 2: Nuh-uh!

What is person 2 committing to? She now has to argue that NOBODY in prison is innocent.
Contradicting "some" (which means "at least one") means "less than one", which is the same as "none".


PERSON 1: "Any effective approach for accomplishing a goal is also a fun approach for accomplishing that goal."
PERSON 2: Nuh-uh.

Person 2 only committed to the idea that she can think of at least one example where something was effective, but not fun.


Hope this helps.