About

We've long been intrigued by the wide diversity of notations in use. Just as some people collect objects – stamps, autographs, beetles, all sorts of things – we have often found ourselves remarking unfamiliar notations, perhaps applauding a clever idea, perhaps thinking that this one obviously won’t catch on.

We are attempting here to try to collect our reflections on a variety of notations; to create a place for thinking about assessing them and making new ones.

Notations can be compared, just like beetles. Some beetles are adapted for living in a woodland, some are adapted for the desert, and yet others are adapted for marshes. A biologist can compare various aspects – the shapes of their mouths, the structures of their legs, and so on, to see how well fitted they are to their particular style of living. Likewise, some notations are designed for one purpose and some for another, and in principle we can compare various aspects to see how well they might be fitted for their context of use. But that means we need to decide what might count as ‘different aspects’ of a notation, and some way to relate those aspects to the ‘lifestyle’, the intended purpose of a notation.

This website focuses mainly on one way to compare notations, something called the ‘Cognitive Dimensions of Notations’ framework, an approach that has proved popular with usability researchers of programming languages in the thirty-odd years since it was first proposed. During that time it has been improved, extended, criticised, and transmuted, but it has never been properly documented, so we thought we ought to, especially as one of us was responsible for the original idea and feels ashamed not have done so before.

And by the way, we have no intention of trying to define what is, and what isn’t, a notation, any more than a book about painting is likely to define ‘art’.

Who we are

Thomas Green started as a psycholinguist, became interested in programming languages, and ended up in HCI. He has published extensively on the psychology of programming, and is the originator of the Cognitive Dimensions. He now enjoys being able to focus on his lifelong hobbies of music and poetry.

Luke Church is a computer scientist working to improve the experience that people have with complex and socio-technical systems, from programming languages and AI platforms to public policy and humanitarian interventions. His work is practice-led and incorporates methods from philosophy, computer science, psychology and critical design.

This website

We've been working for a while now on getting all we know and find interesting written up. Originally imagined as a book, we kept discovering more and more notations people came up with and the text was getting close to 1000 pages, which felt rather untenable to impose on readers. Now in website form, we'll be aiming to publish regularly self-contained posts, and connect them across what we hope will be a useful resource for designers and the curious alike.

Everything is publicly available. By subscribing you can get notified when new content is up, but you can start wherever and dip in and out as desired.