I knew that I was making progress on this project when giving an early demo to my friend Joan. She tried petting one of the Lifeforms, but then pulled back with an "eek" when it responded by moving and purring (in its way).
The goal of the Lifeforms project was exactly this: to make objects that were inanimate, but still capable of evoking the responses in people that living creatures do. Of course I knew that anyone over the age of two would understand that these objects were not alive in the biological sense; what I was aiming to do was to give a credible sensation of aliveness.
I've learned that a participant's intuition be convinced of an interpretation the designer intends (e.g. this object is alive) so long as the evidence supporting that interpretation is greater than the evidence supporting any other interpretation. I'm talking about convincing what Daniel Kahneman would call System 1—the automatic, emotional, intuitive aspect of our brains—while not expecting to make much progress convincing System 2, the thoughtful, calculating aspects of cognition.
In fact, much of my work exploits the frisson that one feels when these systems are put in opposition. When you know intellectually that the furry object that you are touching contains human-made mechanisms, electronics, etc., but still somehow feels alive.
It was important that the Lifeforms were designed to look unlike any known animal. If one looked like a dog, for example, it would be easy for a participant to think "obviously that's not a dog", and the experience would end there. There was no way I could remotely approach the behavioral and physical capabilities of a dog and these failures do so would provide enormous evidence in opposition to the interpretation we were trying to induce.