Information Technology Reference
In-Depth Information
An important counter-part of this easier synchronisation is that it makes synchrony less
representative of shared understanding: agents or people with very different levels of
understanding will be able to synchronise; if sensitivity to non-verbal behaviour is too
high, the dyadic parameter of synchrony is not a cue of shared understanding. By con-
trast, the facility agents trigger non-verbal behaviours when their internal states are high
(threshold
β
) does not appear to change the synchronisation properties of the dyad: the
higher number of exchanged non-verbal signals seems to be compensated by their as-
sociated decrease of precision.
In addition to the effect of shared understanding on the stability of synchrony be-
tween agents, we have tested the effect of shared understanding on the capacity of the
dyad to re-synchronise. For instance, during a dialogue, synchrony can be broken by
the use of new concept by the speaker. That may result in lowering the level of shared
understanding below the
85%
necessary for remaining synchronous. Synchrony can
also be disrupted by an external event which can introduce a phase-shift between in-
teractants. Given fixed sensitivity to non-verbal behaviour (
σ
) and facility to trigger
non-verbal behaviours (
β
), we tested how quickly the dyad can re-synchronise after a
phase-shift. The shared level of understanding necessary to enable re-synchronisation
appeared to be the same as the one under which agents disynchronise.
Two crucial points must be noticed here. First, when agents' understanding do not
differ more than
15%
(shared understanding higher than
85%
), agents synchronise sys-
tematically whatever the phase-shift is, and when agent's understanding differ more
than
15%
they disynchronise. Second, both synchronisation and disynchronisation of
agents are very quick, lasting about one oscillation of the agents' internal states. Syn-
chronisation and disynchronisation are very quick effects of respectively misunder-
standing and shared understanding: agents involved in an interaction do not have to
wait to see synchrony appears when they understand each other, they have a fast answer
to whether they understand each other or not.
The
5000
time steps length of our tests allowed us to test the stability of synchrony
or disynchrony after their occurrence; however it is clearly not a natural situation. Syn-
chrony in natural interaction is a varying phenomenon involving multiple synchronisa-
tion and disynchronisation phases: the level of shared understanding varies along the
interaction. In fact disynchrony may be quite informative for the dyad as its detection
enables agents to adapt one another. In natural interactions, synchrony occurring after
disynchrony shows that agents share understanding whereas they did not before: they
have benefited from the interaction and exchanged information.
As a consequence, the mean level of shared understanding necessary for good inter-
action to take place between persons in natural context would be much more reasonable:
the
85%
of shared understanding occurs in phases of particularly good interaction and
its is not a hard constraint on the whole dialogue; this very high level necessary for syn-
chronisation should be divided by the ratio of synchrony vs disynchrony phases present
in natural interaction. For instance we can imagine that a level of shared understanding
higher than
85%
would occur when people involved in a discussion have just reached an
agreement. By contrast, when the level of shared understanding stays all along the dia-
logue far under
85%
, the dyad would be more like two strangers trying to talk together,
or a professional talking with technical words to a naive listener.
