Dynamics of Trust - Trust Theory: A Socio-Cognitive and Computational Model - page 145

Is Failure due to Ext or Int
factors?

Internal

External

Are they
occasional or
stable?

Are they
occasional or
stable?

Occasional Occasional

Stable Stable

Next time check for similar circumstances or
attitudes and in case reduce the Ext/Int
component of the global trust

Reduce the Ext component
of the global trust

Reduce the Int component
of the global trust

Figure 6.1 Flow-chart to identify the causes of failure/success

Let's first present a basic model (which exploits our cognitive analysis of trust attitude and
the 'Causal Attribution Theory' which are rather convergent), and later discuss possible more
complex dynamics. The following analysis takes into account the stable facts.
We consider a general function by which the agent X evaluates its own trust ( degree of trust )
in agent Y about the task τ (to be performed) in the environment ( DoT X,Y, τ , ):

DoT X , Y ,τ, = f ( DoA X , Y ,τ , DoW X , Y ,τ , e ( )) (6.4)

Where: f (like F ) is a general function that preserves monotonicity. In particular, DoA X,Y, τ is

Y 's degree of ability (in X 's opinion) about the task τ ; DoW X,Y, τ is Y 's degree of motivational

disposition (in X 's opinion) about the task (both DoA X,Y, τ and DoW X,Y, τ are evaluated in the

case in which Y would try to achieve that task in a standard environment: an environment
with the commonly expected and predictable features); e(

τ

) takes into account the part of the
task not directly performed by Y (this part cannot be considered as a separated task but as an
integrating part of the task and without which the same task cannot be considered as complete)
and the hampering or facilitating conditions of the specific environment.
In a simplified analysis of these three sub-constituents (DoA X,Y, τ

(Abilities), DoW X,Y, τ

(Motivations), and e( ) (Environment)) of X 's degree of trust, we have to consider the different

possible dependencies among these factors:

i) We always consider Abilities and Motivations as independent to each other.
We assume this for the sake of simplicity.
ii) Case in which Abilities and Motivations are both independent from the Environment .