Everyone has a blog, or so I’ve been told. So here I am, with a blog of my own. Ostensibly, this is an “academic” endeavor, so I can
pontificate share my thoughts and musings on subjects related to my research field — information theory, particularly as it pertains to decision-making, statistical learning and inference, control, and adaptation.
Why did I decide to call my blog The Information Structuralist? Partly, I was riffing on Dave Bacon’s The Quantum Pontiff and on Kush and Lav Varshney’s Information Ashvins, as well as on the structuralist school. But, more importantly, this name gets straight to the core of what this blog is all about.
The term “information structure” is used in game theory and, through the work of Hans Witsenhausen, in decentralized control to describe the state of knowledge in a multiagent system: an information structure specifies who knows what, when they know it, and what they may expect to know in the future. Kenneth Arrow in The Limits of Organization describes it thus:
By information structure … I mean not merely the state of knowledge existing at any moment of time but the possibility of acquiring relevant information in the future. We speak of the latter in communication terminology as the possession of an information channel, and the information to be received as signals from the rest of the world.
The upshot is that those aspects of information that were intentionally dismissed by Shannon — namely, its timeliness, structure, meaning, and value — must necessarily be brought to the foreground once we begin talking about ways information is (or will be) put to use. This goes sharply against the conventional wisdom that information is measured in the “universal currency” of bits. Once we summon forth all those demons Shannon had tried to banish, we must look beyond the bit and dabble in such unspeakable and eldritch things as sigma-algebras (and partial orders thereof), statistical experiments, information utility, quality of decisions, risk, and even learnability and combinatorial complexity. Fortunately, even when we thus expand our field of inquiry, we do not have to give up the time-tested tools Uncle Claude gave us — we merely need to learn to use them in new, heretofore unimagined, ways.
And that is the raison d’etre of my blog.