Book consists of two essay, one by each of the authors. The first, by Shannon, I read a long time ago, but was unable to understand very well. It was a lot easier to follow this time through, but I'm looking forward to going through this one again in a few years. Almost every book or paper on information theory or communications references this paper (or this book) -- for good reason. It's brilliantly written -- so much of it as I understand. Next time I read it, though, I definitely want to review this Jacobian business. I was lost a few times. (I recall the term from classes in linear and differential equations, but I don't remember what the heck it referred to.)
In the second essay, Weaver discusses the 3 levels of communication: a) the engineering level, b) the semantic level, and c) the action level. The engineering level is concerned with the transmission of data. The semantic level is concerned with the meaning of the data. And the action level concerns getting the recipient of the information to act on the data in the manner that the sender wishes. I think this aspect of communication is often overlooked, when it is ever considered. Weaver discusses the relationship between these levels.
He's got a cool quote from Authur Eddington on the last page, but Weaver suggests something very interesting shortly before that quote when he says,
"One has the vague feeling that information and meaning may prove to be something like a pair of canonically conjugate variables in quantum theory, they being subject to some join restriction that condemns a person to the sacrifice of the one as he insists on having much of the other."
This is a very intriguing speculation, I think, and the discussion leading up to this is much easier (and well worth it, I'll add) than the preceding explanation by Shannon. Shannon's work is very much intended for an engineering audience, while Weaver's seems more general.
I'll add that I've been browsing a few unrelated things. I found a letter from Jacques Derrida to a Japanese friend in which he claims to be trying to explain what 'deconstruction' is so the friend can translate the term into his own language. I've heard this term used by other people for years now and had no idea what the heck they were talking about. And now that I've read this letter, I'm no closer. But I will say this: I felt a strong sense of deja vu when reading this letter -- it took me back to when I was reading snippets of Edgar Cayce. It all seems either obvious or nonsensical. It's just a letter, I suppose. Not intended perhaps as the definitive exposition. Still, it reads like stereo-typical social "science". In any case, I did get another reference to a complete book that perhaps will explain things in a way I can understand.
