Information Technology Reference
In-Depth Information
2.2
i*-
Context for Web Service
Incorporating results from current context-aware system practices, where location,
identity, activity and time related information are used to capture the service
context[3]. We propose to extend the current i* concept by putting the position
occupation and role playing relation under context. In other words, the agent-position
and position-rolerelationship may vary according to physical context such as time,
location, etc. Thus, we use service user's social positions and his agent classesas
i*
-
Context to capture and model the diversity of service settings.
Table 1.
Categories of Social Positions and Agent Classes in
i*
-Context
Category
Examples
Social Position
Occupation
Position[
athlete
],
Position[
coach
]
Family
Position[
father
]
Position[
daughter
]
Hobby
Position[
golf club member
]
Position[
classic music fan
]
Agent Class
Demographical
Agent Class[
male
]
Agent Class[
teenager
]
Cultural
Agent Class[
Buddhist
]
Physical
Agent Class[
wheel chair user
]
Education & Skill
Agent Class[
C++ expert
]
Habit
Agent Class[
vegetarian
]
Table 1 shows some example categories of social positions and agent classes used
in
i*
-Context.As individual agent may occupy more than one social positions at a
time, the importance of each position under certain physical conditions is also
modeled in the
i*
-Context.
Back to our case Study, Table 2 shows the
i*
-Context of a Paralympics athlete,
John. Being an athlete and father of a six year old girl, Johnis also avegetarian,
Chinese, practicing Buddhism and using a wheel chair.This information brings John
the social positions of
Position
[
Father
],
Position
[
Athlete
], and also reveals the agent
classes John belongs to, such as
Agent Class
[
vegetarian
],
Agent Class
[
Chinese
],
Agent Class
[
Buddhist
] and
Agent Class
[
wheel chair user
]. Along with these social
positions and agent classes,
i*
-Context also provides importance ratings for social
positions in various physical contexts. To keep the problem clear, we use a simplified
importance value to represent the importance of social positions.
Based on our observation, although individual agents may have more than one
social positions at a time, there is usually one position that surpasses all others in
importance, and decides what kind of action the agent should performina
givenphysical context. Hereby, we introduce the concept of “foreground position”.
•
Foreground Position
: Foreground position is the social position that overweighs
all other social positions in importance in a certain physical context for a particular
agent.Define
Positions(
Agent[
a
]
, pc)
asthe set of all social positions Agent[
a
] plays
in certain physical context
pc
.
