“We don’t really believe everything we have written in this book,” say the authors, environmental scientist David Sarokin and neuroscience professor Jay Schulkin. It is one of the strangest opening sentences for a book’s epilogue I think I’ve ever read – so strange that I had to go back and read it again. Having done so, I’m still not quite clear what they mean.

But then again it would be a mistake to believe anything just because it is labelled ‘information’, especially the mixture of tittle-tattle, fact, history and gossip you find on the internet – and this may have been their point. That is the problem with information in the Information Age: some of it is junk, but it isn’t immediately clear which.

The authors have also achieved something important: a book about information that is written by neither a cynic or sceptic nor a true believer in the IT revolution. It is also a clearly written guide to what is not yet a proper debate.

Sarokin and Schulkin make a good case for one of the central paradoxes: we live with screeds and screeds of data about aspects of our lives, our habits and our health, but concerning some important aspects of modern life there is an extraordinary dearth of information.

Their examples are written from an American standpoint, which means they emphasise how difficult it is to find out anything about malpractice suits against your doctor, anything about the ethics or sustainability of products on Amazon, or whether your milk has come from cows fed with bovine growth hormone (though you can sometimes find it indicated if it hasn’t).

From a UK perspective, you might add how difficult it is to find out anything about the terms under which companies run our public services. It might also be good for British readers to remember the episode of the ‘traffic light’ signs that Sainsbury’s introduced on their food packaging, and how the food industry combined around rival signage that provides so much information that it is virtually useless.

I wish the book had gone a little further about the importance of informal information and how it gets downgraded by information systems that fail to understand it or value it. Perhaps the best UK example might be the way the big banks have become virtually unable to lend effectively to small businesses because – without a professional cadre of bankers at local level – they no longer have access to the kind of informal information that bank managers used in the days of Captain Mainwaring.

The result is a bizarre and increasing economic centralisation, which unbalances the economy and makes places more dependent than they would otherwise be. And all because some kinds of information are not accessible except by people on the spot.

Then there is all that informal information we need about institutions but can’t find online. We know how well our local school pupils do in their exams, we can read the computerised read-outs of Ofsted inspection reports, but we still don’t really know if the school would be right for our child. That sort of information is only really available from meeting the teachers, spending time in the school, and talking to other parents. It isn’t statistical.

Missed Information touches on this, perhaps most graphically in the phrase “death by GPS, when people so trust the extremely limited information on their car’s sat-nav system that they happily drive into rivers or into the path of oncoming trains”. There in a nutshell is the difference between official, canalised information and the kind of local detail that we sometimes need to know very much.

What makes this book important is the authors’ conviction that the word ‘information’ is now too broad to be adequately meaningful. We need new words to cover different aspects. And may I suggest that when we get them, we call informal information ‘knowledge’?

David Boyle is the author of Ronald Laing: The Rise and Fall and Rise of a Revolutionary Psychiatrist (The Real Press).