So I mentioned in the intro to this review that I was drawn to review Doctor Strange (with my buddy and co-reviewer Scout Addis) because the Cloak displays some interesting qualities in relation to the book I just published. Buy it, read it, review it on amazon.com, it’s awesome.
That sales pitch done, I can quickly cover the key concepts here.
- A tool, like a hammer, is a familiar but comparatively-dumb category of thing that only responds to a user’s input. A hammer is an example. Tool has been the model of the thing we’re designing in interaction design for, oh, 60 years, but it is being mostly obviated by narrow artificial intelligence, which can be understood as automatic, assistive, or agentive.
- Assistive technology helps its user with the task she is focused on: Drawing her attention, providing information, making suggestions, maybe helping augment her precision or force. If we think of a hammer again, an assistive might draw her attention to the best angle to strike the nail, or use an internal gyroscope to gently correct her off-angle strike.
- Agentive technology does the task for its user. Again with the hammer, she could tell hammerbot (a physical agent, but there are virtual ones, too) what she wants hammered and how. Her instructions might be something like: Hammer a hapenny nail every decimeter along the length of this plinth. As it begins to pound away, she can then turn her attention to mixing paint or whatever.
When I first introduce people to these distinctions, I step one rung up on Wittgenstein’s Ladder and talk about products that are purely agentive or purely assistive, as if agency was a quality of the technology. (Thabks to TU prof P.J. Stappers for distinguishing these as ontological and epistemological approaches.) The Roomba, for example, is almost wholly agentive as a vacuum. It has no handle for you to grab, because it does the steering and pushing and vacuuming.

Yes, it’s a real thing you can own.
Once you get these basic ideas in your head, we can take another step up the Ladder together and clarify that agency is not necessarily a quality of the thing in the world. It’s subtler than that. It’s a mode of relationship between user and agent, one which can change over time. Sophisticated products should be able to shift their agency mode (between tool, assistant, agent, and automation) according to the intentions and wishes of their user. Hammerbot is useful, but still kind of dumb compared to its human. If there’s a particularly tricky or delicate nail to be driven, our carpenter might ask hammerbot’s assistance, but really, she’ll want to handle that delicate hammering herself.
Which brings us back to the Cloak. Continue reading →