What you have growing wild in your yard is the ancestor of Belgian endive. If you did the same process with it, you would probably get a very loose collection of blanched leaves, not the tight heads of Belgian endive.

The Italian chicory is yet a different variety of the same speices, grown for its dandelion like foliage (I assume you're talking about the Italian Dandelion, not the headed varieties). Forcing it would probably be the same basic results, loose leaves instead of a tight head.

Well...I have several different kinds. Some have very dandelion-like leaves. Some have smooth leaves. There's one that is sort of curly, and while I wouldn't call it a "head" exactly, it's more head-like than many of the others. I know that at least some of them will get very tall and produce purple daisy-like flowers, but I haven't been paying close enough attention so know exactly which of them will do it -- I think it's the one with the dandelion-like leaves. This one grows wild all over my area, and I've also seen it growing on the roadside in Germany.

My Italian neighbor tried to explain the different kinds of chicory to me, but her English is only so-so, and my Italian is nonexistent. She called one kind "Catalanian" or something like that. When she spoke of different varieties, she gestured to her hair (which is curly) and my hair (which is straight), and said "It's like that." She said that one of the things growing in my garden was escarole (which she says came from my neighbor on the other side, who speaks even less English), but I'm confused about whether she was trying to say that this was yet another kind of chicory, or if it's something different. She said I can cook them all the same way.

At any rate, I only recently realized that Belgian chicory was anything like the same thing at all, so I started to wonder. Maybe I should try it, if I can find the space to let some of these grow out over the Summer.