IEEE Consumer Electronics Magazine - July 2018 - 29

(Figure 2). The set of states and their transactions are detailed
as follows.

In a collaborative state, the
host user is the only one who
interacts with the RO.

STATE 0: INITIAL STATE
In this state, the user is connected to the virtual space and is
able to interact with objects and other users. When the user
starts a recommendation session (i.e., the activation action) by
means of a shopping element in an available RO (action A),
the recommender creates an individual user model (the set of
critiques the user has performed during the recommendation
process) for the user. The user then proceeds to state 1 (the
individual recommendation state).

STATE 1: INDIVIDUAL RECOMMENDATION STATE
Here, the recommender offers a product to be shown in the
RO. The user can perform one of the following four actions
in this state:
1) Individual critiquing (action B): This action consists of
making unit critiques through the critique elements in the
RO. For each critique, the recommender provides a new
product recommendation, and the user model is updated to
include the new critique. This action keeps the user in the
same state (state 1).
2) I like (action C): This action is activated by means of a
collaborative element in an RO of another user (see the
upper half of Figure 1) and occurs when one user wants
to collaborate with another (i.e., when the user likes the
recommended product shown in another's RO). The user
who starts the collaboration is called the guest user, and
the other user is called the host user. Following this

A:
n te er
o
ti va nd
Ac cti me
A m
co
Re

State 1:
Individual
Recommendation

STATE 2: COLLABORATIVE RECOMMENDATION STATE
A user moves to this state when he or she starts the collaboration (guest user) or when someone wants to collaborate with
the user (host user). In a collaborative state, the host user is the
only one who interacts with the RO. In this sense, the host user
acts as a leader of the whole set of collaborators. Reaching a
consensus may be achieved using communication tools
(through text or voice chat) in the 3-D virtual environment. If
guests do not agree, they can decide to leave the collaborative
state at any time using the "I leave" collaborative element.
The following four actions are performed in this state:

State 0:
Initial

:
G
n n
io do
t
Ac ban
A

Action C:
"I Like"
Action E:
"I Leave"

H:
n t
tio en
Ac aym
P

Action B:
Individual
Critiquing

action, both users move to state 2 (the collaborative recommendation state).
3) Buy it (action F): This action occurs when the user has
found a suitable product, and it is activated by means of a
shopping element in an RO, as shown in Figure 1. The
user then moves to state 3 (the buying state).
4) Abandon (action G): This action is activated by means of a
shopping element in an RO. It happens when the user explicitly finishes the recommendation process because he or she
does not find a suitable product and returns to state 0 (the initial state), where he or she can start a new recommendation.

Action G:
Abandon

Action D:
Collaborative
Critiquing

State 2:
Collaborative
Recommendation

Action F:
"Buy It"

State 3:
Buying

Action F:
"Buy It"
FIGURE 2. A model of the users' states.

July 2018

IEEE Consumer Electronics Magazine

Table of Contents for the Digital Edition of IEEE Consumer Electronics Magazine - July 2018