Table 2. Example of trial-per-trial free-text subjective reports. Participants were asked to very briefly describe their experience of the other's presence after each trial. The following example illustrates a typical development across the 15 trials from the players' perspectives. In the first few trials the other's presence is obscured, but soon players start to become aware of the other's presence by noticing themselves to be the object of the other's searching movements. After a few more trials a turn-taking (TT) interaction starts to take shape, alongside a clearer presence of the other. This allows for some communicative intentions to be felt and shared. Some uncertainties arise while the conventions of mutual interaction are negotiated and modified over later trials, but co-presence tends to be re-established reliably. All clicks correctly identified the other player's avatar (PA).

Trial	Player	Describe the sensation of your partner's presence:	Click	PAS	TT
1	1	I wasn't sure if it was actually the partner's avatar or just a moving object.	PA	2	0
	2	She moved as if she is not just random, she seemed to know it's me.	PA	4	0
2	1	by the avatar's “exploratory” movement,	/	/	/
	2		/	/	/
3	1	I think I “found” the partner's avatar quite close to the static object? So I wasn't sure if it was actually the avatar or the static object.	PA	2	0.25
	2	vaguely	PA	2	0.08
4	1	I tried to compare the difference in sensation by looking for the static object and the partner's avatar. The difference was very clear.	PA	4	0.48
	2	Ah, it's she!	PA	4	0.43
5	1	the partner's avatar was again moving around my avatar	PA	4	0.22
	2		/	/	/
6	1	even when I stopped moving, I would receive a irregular feedback	PA	3	0.17
	2	Clear experience! It's she! She is alive!	PA	4	0
7	1	I wasn't sure if it was a moving object or the partner's avatar.	PA	3	0.20
	2	Ah, I come to understand now to recognize her!	PA	4	0.24
8	1	I wasn't sure if I got the partner's avatar.	/	/	/
	2		/	/	/
9	1	I think there was a turn-taking-like communication.	PA	4	0.52
	2	She likes me!	PA	4	0.31
10	1	It looks like we've established a way to communicate.	PA	4	0.40
	2	I came to wonder if it is only an object. How can I feel it.	/	/	/
11	1	clear!	PA	4	0.20
	2	Only objects cannot locate as this.	PA	4	0.14
12	1	presence of an intelligent object	PA	4	0.40
	2	Clear, but afterward she escaped from me, which makes me wonder if that was really her, but only an object.	PA	4	0.32
13	1	wasn't sure if it was the partner's avatar	PA	2	0.03
	2	Sorry I forgot clicking.	/	/	/
14	1	It felt clearly that we were trying to tell each other that we found ourselves.	PA	4	0.30
	2	I guess it may be her, but she tends to escape (this was not clear to me) from me.	PA	3	0.40
15	1	Felt like she found me.	PA	4	0
	2	It's she!	/	/	/