Pedants please enlighten me

[MrsFogi]

"In comparison to" or "In comparison with" and when? I have had no luck finding an explanation online or in a dictionary.

IMHO this is to do with what kind of comparison you are doing. Comparing to is done when you are doing to explain that two things are comparable; comparing with is done to establish the differences. Shakespeare says "shall I compare thee to a summer's day?" in Sonnet 18 because he wants to point out, rhetorically, that a summer's day isn't even in the same ball park, not because he's interested in the detailed differences between the person he's talking to and the weather.

So I reckon you would use "in comparison to" only when you are considering whether two things can be compared at all ("A fish, compared to a bicycle, is edible") as opposed to the differences between them ("a Moulton, compared with a Raleigh, is very expensive, though not when compared with a Lamborghini")

My mum (pedant-in-chief) always said " compare to, contrast with."

Thank you prism and nigglewiggle. Prism has raised another need for enlightenment - by the looks of the post I "do" a comparison rather than "make" one?

What a shame we're not speaking French then there would be no difference. A comparison is a noun, so you make it; comparing is a verb, so you do it.

IMHO.