
 
The main menu shows the options concerning the 
domain (binary trees, AVL trees, and B trees), 
didactic material for download, and an option to 
activate the Help system and the following 
submenus include concepts, tree operation 
simulations and proposed exercises about insertion, 
removal and search operations. 
CoolED also presents chats to allow student 
group discussion; a forum, which acts as a repository 
of topics of interest for discussion, where students 
and professors may participate; an agenda or 
planner, where the professor posts deadlines for 
activities and meetings; and an animated agent that 
acts as a mediator in the collaborative process, 
stimulating participation of all group members, 
observing the development of activities, and 
assisting the decision-making process as well. 
4.2 The Agent 
The agent is responsible for the student-environment 
communication interface. It acts as mediator, 
intervening when the student, for instance, 
experiences difficulties in using a CoolED tool or in 
conducting exercises and also when choosing the 
group leader. The term mediator was constructed 
from the concept of mediated relation described by 
Vygotsky and is based on the behavioral analysis of 
a teacher in a classroom who follows a social 
constructivist approach. 
In the developed prototype the agent’s figure is 
represented by Peedy, an animated agent developed 
by Microsoft that is available free of charge. Peedy 
possesses a few movement functions, appearance 
and text balloons. The remaining functionalities are 
being developed by LAVI.  
The following functions pertain to the agent: 
 Warning – shown to the students every time 
new information is included by the professor in 
the Planner, when material is available for 
download, and when interest topics are inserted 
in the Forum; 
 Assistance – provided whenever the agent 
notices that a student faces difficulties in solving 
the exercise, when there is lack of 
communication between group members or when 
communication is unilateral; 
 Correction – at the end of an exercise, the agent 
compares the group answer to the exercise 
solution; 
 Decision-making – for a solution of each 
exercise, the agent uses the leadership model for 
determining which student will lead the group. 
 
4.3  CoolED’s Decision-making Process 
In solving exercises collaboratively, group decision-
making is conducted by a leader, who is selected by 
the agent, considering evaluation criteria described 
in the leadership model. The student chosen as a 
leader is the only one who conducts insertion, 
removal and search operations in trees, and the role 
of the remaining students is to participate in the 
solution of the exercise, expressing their opinions 
through the chat room.  
In the model of leadership each student has a 
leadership reputation grade that corresponds to the 
probability of being chosen to be leader and a 
variable that indicates how many times the student 
has already been a leader. The system initially 
bestows grade 5 to each student, hence all students 
are equally likely to become leaders. As students 
lead the exercises, their grades vary from 0 to 10, 
where 0 means least likely to be chosen and 10 
means most likely to be chosen. Grades start at 5 
because, after each leadership, a student can have his 
or her grade increased or decreased depending on his 
or her performance. Whenever there is someone in 
the group who has not yet been leader, this person 
will always be chosen. The number of times a 
student has been a leader will also be taken into 
consideration, and priority is given to those who 
were leaders the least often. In case of a tie between 
the grade and number of times two people were 
leaders, both will have the same chances of being 
chosen, and the agent will randomly select one of 
them.  
At the end of each collaborative student-led 
exercise, the group will answer an evaluation survey 
that aims to analyze leadership performance, and 
thus serve as a positive or negative weight for the 
leadership grade. CoolED possesses two types of 
surveys, one for group members lacking leadership 
functions and another for leader self-evaluation. The 
self-evaluation questions induce leaders to reflect on 
their performance in this role and their interest in 
repeating the experience. The other survey makes 
the remaining participants of this work session to 
analyze the leader’s role and investigate whether 
they wish to work with this leader again. The result 
after compilation is presented by the agent to the 
leader. 
4.4 Implementation 
The CooIED system is in a final stage of 
development taking as a basis the Document of 
Requisites Specification,   the Entity-Relation  
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