Web-based Learning Solutions for Communities of Practice

Figure 7. Showing and sorting results
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P j
I ij
T = w * E + w * P + w * I +( ij e j p j i ij
j= 1
QC )/n ij
(1)
n
∑
where E is the value of expertise which
j
is calculated according to the degree of
experience that the person upon whose
behalf the agent acts has in a domain. In
this case the domain of the community
which the agent wishes to join.
is the value assigned to a person’s position.
This position is defined in the
agent’s internal model of the reactive
architecture described in Section 4.1.
denotes the intuition value that agent
i has in agent j which is calculated by
comparing each user’s profile.
In addition, previous experience should
also be calculated. When an agent i
consults information from another
agent j, the agent i should evaluate how
useful this information was. This value
is called QC (Quality of j’s Contribu-
ij
An Agent System to Manage Knowledge in CoPs
tion in the opinion of i). To attain the
average value of an agent’s contribution,
we calculate the sum of all the
values assigned to these contributions
and we divide it between their total.
In the expression n represents the total
number of evaluated contributions.
Finally, w e , w p and w i are weights with
which the trust value can be adjusted
according to the degree of knowledge
that one agent has about another.
2.3. For each agent in the group (the results
group) that the agent has no previous
experience it calculate a trust value as
we mentioned in 1.3.
2.4. The user agent shows the results, which
are sorted by trust or quality values as
in the previous situation.
3. If the user agent has enough previous experience
(this is considered when an agent has
interacted many times with another. This
number of interactions depends on a threshold
that can be adjusted to each domain) then
the user agent calculates the trust value by
only using the previous experience factor.
In this case we only consider this factor
(experience) because this is the principal
factor that humans usually consider when
they have to trust somebody/something.
That’s why this concept is the base of all
trust models described in literature as it will
be explained in section 7. In this context the
user agent follows the following steps when
looking for documents about a topic T:
3.1. The user agent follows step 2.1
3.2. For each agent in the group (the results
group) the user agent calculates a trust
value by using the previous experience
factor that is, by using (2) which is the
last part of formula (1),
n
(
j= 1
∑QC ij )/n (2)