My PST 2022 Keynote

“You keep using that word. I do not think it means what you think it means” (Yes, it’s about how trust is co-opted and overloaded.

You can download the slides by clicking on the link below.


We have come a long way, haven’t we?

30 years ago this summer, the first article on Computational Trust was published and presented in a small Multi-Agent Systems workshop in Italy. At which point lots of interesting things began to happen, for many different reasons, perhaps the biggest of which was the arrival of the public Internet and the Web.

The result? Not really what I expected!

Multiple models, plenty of applications (perhaps there’s a link between the two?!), increased understanding perhaps, increased complexity certainly, and now a bunch of thoughts about AI.

And security.

Some time ago, Dieter Gollmann pointed out that trust was ‘an absolute mess’ and was not the unifying theme for security people seem to think it is (or was).

Maybe. Probably.

But don’t vendors love to tell us we can trust their systems? Isn’t it lovely when we can look at trust-marks, or reviews, or reputation, and other more violent means of controlling people. Like social credit, for example.

Here’s the thing: ‘trust’ is so overloaded a term as to be useless, so it’s probably time to figure out what on earth we are talking about when we are talking about trust. Because, as we all know, Inigo Montoya was right.


Stephen Marsh is an Associate Professor of Trust Systems at Ontario Tech University. His research expertise covers areas as diverse as human-computer interaction, wisdom, trust, regret, forgiveness, energy management, hope, privacy, communications security, socially adept technology, and democracy. He is currently examining Trustworthy AI from the perspective of AI trusting people as well as the other way around ( His seminal work on Computational Trust brought together disciplines of cognitive science, psychology, philosophy, sociology and computational sciences , founded a new research field in Computational Trust, and has continued to influence the field for almost three decades.

Steve lives on a nano-farm in Eastern Ontario, from where he builds stuff, teaches, makes music (his album will be out in October!), draws (badly), writes (Trust Systems the textbook is freely available as an Open Educational Resource at [](, he is currently working on a fiction trilogy and a non-fiction book about Hope), blogs occasionally at and shares life with people, dogs, cats, horses, a pig, sheep, goats, chickens and lizards. He quite possibly also has bats in the belfry.