To compare A to B is to say A is like B (Shall I compare thee to a summer's day?)

To compare A with B is to examine their common features and differences.

In your examples:

A) The last three are idiomatic, the first two not really (or at least substitute "a" for "the" -- and then they mean the same)

B) Of the last three, for the difference between 3 and 4, see above (presumably you mean "with"). 5 means the same as 3.

Ah vielen dank und wie sieht's mit between versus of aus?

Niemand eine Idee?

Wirklich niemand?

No ideas, because the question "wie sieht's mit between versus of aus?" isn't really clear.

The question was, what is the difference in meaning (or usage) between these versions:

The comparison of A and B is difficult.
The comparison between A and B is difficult.

Cum grano salis:

Whats the difference between these sentences.

1. Scientists have made a comparison of molecules and atoms in the past.
2. Scientists have made a comparison between molecules and atoms in the past.
3. Scientists have compared molecules with atoms in the past.
4. Scientists have compared molecules to atoms in the past.

when to use "comparison of" , "comparison between" & "comparison to"

To my ear, the verb version and the noun version are interchangeable. "To compare" is "to make a comparison."
I compared A to B.
I compared A and B.
I compared A with B.
I made a comparison of A and B.
I made a comparison between A and B.
I made a comparison of A to B.
Comparing A and B, A is larger.
Comparing A to B, A is larger.
By comparison, A is larger than B.
A, compared to B, is larger.
A, compared with B, is larger.
Compared to B, A is larger.
Compared with B, A is larger.
(Some of these may be a [at a] lower register.)

http://www.englishforums.com/English/Comparis...

Mr Lehmann ? RSO-Meerbusch !
What are you doing here ?

Some of the examples given by translothar do not reflect careful usage. This is not a pedantic matter, as meanings are at stake.

"to compare A to B" means "to assert that A is like B". It makes no reference to differences. This also applies to all derivatives. Thus his/her example

A, compared to B, is larger
Compared to B, A is larger
Comparing A to B, A is larger

do not make sense.

Shakespeare's sonnet begins: Shall I compare thee to a summer's day?

It doesn't mean: a summer's day has qualities x, y, z and you have qualities p, q, r (as it would have done if S. had said "compare thee with").

His other sentence

By comparison, A is larger than B

does not mean what he suggests. The expression "by comparison" refers to what has gone before. As in:

Hooke was a brilliant scientist; by comparison, Newton was a vain and petulant plagiarist.

Super, vielen Dank Translothar und Escoville!