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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Providing Relevant Knowledge in Disputes: UMCourt Project</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Davide Carneiro</string-name>
          <email>dcarneiro@di.uminho.pt</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Ângelo Costa</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Paulo Novais</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Francisco Andrade</string-name>
          <email>fandrade@direito.uminho.pt</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>José Neves</string-name>
          <email>jneves@di.uminho.pt</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Informatics, University of Minho</institution>
          ,
          <addr-line>Braga</addr-line>
          ,
          <country country="PT">Portugal</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>School of Law - University of Minho</institution>
          ,
          <addr-line>Braga</addr-line>
          ,
          <country country="PT">Portugal</country>
        </aff>
      </contrib-group>
      <fpage>63</fpage>
      <lpage>77</lpage>
      <abstract>
        <p>Parties involved in disputes often lack the information they need to take rational decisions. As a consequence, they frequently enter into agreements that are not as advantageous as they could be. Having the right information in the right time would guide parties into taking more weighted and realistic decisions. Specifically, parties should consider their best, worst and most likely outcomes in litigation as well as all the possibilities in between. In this paper the importance of this information is highlighted and domain-dependent methods for compiling it are presented. Moreover, this work describes three case studies in which these methods are being applied with the objective of informing the parties, empowering their role in the dispute resolution process and helping them achieve more satisfactory outcomes.</p>
      </abstract>
      <kwd-group>
        <kwd>Online Dispute Resolution</kwd>
        <kwd>Case-based Reasoning</kwd>
        <kwd>Rule-based Systems</kwd>
        <kwd>UMCourt</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>Conflicts arise in the most different scenarios and are present in our day-to-day since
our first years of life. Essentially, conflicts are due to the competitive nature of our
society, in which each individual wants to maximize his personal gain. A conflict is
generally defined as an opposition of interests between two persons. When two
persons with opposing interests clash, a dispute arises, that will eventually need to be
settled. Each of these persons has ideas and values of its own that will guide and
support his actions throughout the dispute resolution process.</p>
      <p>
        Until just a few years ago, these conflicts occurred mainly between two persons
that where on the psychical presence of each other. However, given the new
information society that we now live on, this is no longer necessarily true. In fact,
online activities, such as the use of e-commerce sites amazon.com and ebay.com, have
led to the development of on-line disputes. We argue that if a transaction occurs
online, then disputants are likely to accept online techniques to resolve their disputes.
Thus, the development of e-commerce requires new ways of resolving conflicts that
avoid courts. Different forms or methods of alternative dispute resolution for
electronic environments have been pointed out by legal doctrine. Thus being, we can
now speak of Online Dispute Resolution (ODR) as any method of dispute resolution
in which wholly or partially an open or closed network is used as a virtual location to
solve a dispute [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]
      </p>
      <p>
        A relevant issue, in a first moment, will be to inquire in what way (and to what
point) traditional mechanisms such as negotiation [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ], mediation [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] or arbitration
[
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]can be transplanted or adapted to the new telematic environments, taking
advantage of all the resources made available by the newest information and
communication technologies. However, technology can be used for much more
important tasks such as strategy definition, information retrieval, solution proposal,
among others. In order to develop such intelligent and efficient techniques to support
Online Dispute Resolution, we must also consider the integration of Artificial
Intelligence with Online Dispute Resolution [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. This knowledge can be considered
from two different perspectives: on the one hand, as a tool to help the parties and the
decision makers to obtain the best possible results in solving commercial disputes
and, on the other hand, considering a new way of autonomous dispute resolution
through the use of autonomous and intelligent software, supported by a knowledge
base and decision capabilities.
      </p>
      <p>
        The work presented here develops around these two main ideas. We will therefore
analyze to what extent technology can be used to help parties achieve more
satisfactory solutions. Specifically, we will look at several methods for efficient and
contextualized information retrieval as a way to provide meaningful information that
is not available in traditional procedures. Moreover, we will look at three novel ODR
prototypes developed with the objective of fastening and making more efficient
dispute resolution processes. These prototypes are supported by UMCourt, an
agentbased architecture that supports the development of ODR services [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>Throughout this paper we will be guided by a main idea: there is not one single
technological solution that can address all the problems. In that sense, techniques and
procedures should be chosen and adapted according to each specific legal domain.</p>
    </sec>
    <sec id="sec-2">
      <title>2 UMCourt</title>
      <p>
        On-line dispute resolution methods can provide easy, efficient and fast ways for
resolving disputes, contrary to the judicial path which is usually expensive and time
consuming. First and second generation ODR [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ], with agents performing relevant
parts of the agreement procedure can be of inestimable use for the parties. UMCourt
is a project being developed at University of Minho in the context of the TIARAC
project (Telematics and Artificial Intelligence in Alternative Conflict Resolution) that
aims to develop tools to help parties involved in legal disputes. Currently, four
domains are object of study: labor law, consumer’s law, divorce and heritage’s share
and conflicts in Virtual Organizations. In that sense, a high level architecture is being
developed that can be used in the different legal domains.
      </p>
      <p>
        This architecture is built on the notion of intelligent agent [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. Thus, it builds on a
group of autonomous software entities that are able to proactively make decisions and
cooperate in order to achieve the objectives. Specifically, we are working with Jade
platform which provides several interesting agent management and communication
services [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ]. In order to be able to address different legal domain with as much
functionality reuse as possible, a development strategy was followed that organizes
the agents of the architecture into two categories: high level agents and low level
agents. High level agents perform tasks that do not need explicit domain-dependant
information. Low level agents are closer to the legal domain, thus have methods for
representing domain-dependant information and procedures. In a general way, high
level agents coordinate low level ones, i.e., the first tell the seconds the steps to follow
in order to implement a given behaviour. Low level agents then have the knowledge
that allows them to decide what to do in each step, according to the domain of the
tasks. This knowledge is formalized in ontologies that encode the domain concepts,
actions, constraints and rules.
      </p>
      <p>This is possible to do because there are procedures that are independent of domain.
Let us take as example a negotiation process. This generally consists on several
consecutive rounds in which each agent states an opinion about the proposal currently
on the table. And this is independent of the domain of the negotiation. Thus, high
level agents guide the process and determine when a new round should start, the turn
of the several agents or when the process should finish. Each low level agent then has
the autonomy to choose among the several actions in the knowledge base, the one that
corresponds to the current domain of the negotiation.</p>
      <p>Following this approach increases functionality reuse and allows to have a single
architecture supporting services in a wide range of domains. It also simplifies the task
of adding a new legal domain. In fact, in order to do so, it is generally only necessary
to develop the ontology of the new domain, with all the actions, rules, constraints and
specific concepts. This will tell the low level agents how to act when they receive a
task from this new domain.</p>
      <p>
        Let us now move to a close description of the architecture. At the moment, it
implements two high level functionalities: a case-based reasoning (CBR) [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ]
algorithm and a negotiation one. The CBR functionality enables a wide range of
services used mainly to inform the parties based on other similar cases. The
negotiation functionality allows two or more agents to exchange messages in order to
iteratively modify a proposal for a solution until an agreement is reached.
      </p>
      <p>All the agents and their roles are depicted in Table 1. These agents were defined
after the specific requirements of this project, following an iterative cut-down process
of increasing specification. Nevertheless, given the open nature of the architecture, it
can be easily extended by adding new agents or ontologies, namely to address other
legal domains or to implement new functionalities in a domain.
Reviser</p>
      <sec id="sec-2-1">
        <title>Case Loader</title>
      </sec>
      <sec id="sec-2-2">
        <title>Roles</title>
      </sec>
      <sec id="sec-2-3">
        <title>Database</title>
        <p>FSA</p>
        <p>Indexer
l Parser
e
v
e
l
w
lo Rules</p>
      </sec>
      <sec id="sec-2-4">
        <title>Selector</title>
      </sec>
      <sec id="sec-2-5">
        <title>Settings</title>
      </sec>
      <sec id="sec-2-6">
        <title>Similarity</title>
      </sec>
      <sec id="sec-2-7">
        <title>Interface Agents</title>
        <p>Extension
l
o
trn Coordinator
o
c
actions to adapt a given case so that it can be used.</p>
        <p>Looks at a group of cases in order to select an
outcome/solution for a given case. Proposes the outcome to the
coordinator as well as a justification and waits for the outcome.
If the outcome does not comply with the one suggested
provides a list of more probable reasons for the failure.
Agents request case information to this agent. This agent
provides the cases by interacting with the Parser agent. Each
case that is requested is maintained in memory so that, should
they be requested again, they are rapidly available in memory
and do not need to be parsed again. This agent also checks
constantly for changes in the files of the cases that are in
memory in order to maintain them synchronized.</p>
        <p>Contains a list of agents and the actions that they are
authorized to perform.</p>
        <p>Is responsible for implementing services to implement all the
interactions with the database. It is also responsible for the
security and integrity of the database, making sure that only the
correct agents perform the authorized operations.</p>
        <p>Contains a list of Jade FSM behaviors that describe the
guidelines or steps necessary for an agent to perform defined
actions.</p>
        <p>Indexes new cases in the Database and creates the specific xml
files in the correct system folders.</p>
        <p>Verifies the validity of XML files against the defined schemas.
Valid cases are parsed and returned as a Java Object that can
be handled by other agent.</p>
        <p>Embodies rules of type if condition then action that provide
basic reactive actions for guiding agents in the decision making
processes. Can be used to model a rule-based legal domain.
Multiple instances of this agent exist that implement different
pre-selection algorithms. Some have already been
implemented, such as the Template Retrieval while others (e.g.
Clustering algorithms) are now being developed.</p>
        <p>Defines several search and similarity settings according to
which retrieve parameters can be changed.</p>
        <p>Multiple instances of this agent embody different similarity
algorithms.</p>
        <p>This agent represents a group of agents that have as task to
gather information from html forms. Then, they compile that
information and forward them according to the defined format
to the agents in the backend. As each html page in the frontend
generally has, at least, one agent and they perform relatively
simple tasks, we will not detail them further here.</p>
        <p>This agent receives requests from external agents and forwards
them to the correct agents inside the platform, provided the
external agents are trying to perform an action that they are
authorized for.</p>
        <p>Receives task requests from other agents (e.g. external agents,
interface agents) and take the necessary steps (requesting tasks
to other agents) in order to perform them. This agent maintains
a list of active tasks and has access to a list of finite state
Fault Manager</p>
      </sec>
      <sec id="sec-2-8">
        <title>Load Balancer</title>
        <p>automata that define the next action for each task, provided by
the FSA agent.</p>
        <p>Starts all the necessary agents according to an editable XML
configuration file. It then constantly checks the agent registry
and, if any agent has crashed, restarts another instance of that
agent.</p>
        <p>This agent controls the pending requests to specific secondary
agents and starts new instances of agents that have a significant
amount of work load.</p>
        <p>The organization of this agents is depicted in Figure 1. In this figure, rounded
rectangles represent agents and the lines represent the main communication paths.
Note the existence of the DF agent (Directory Facilitator), an agent that makes part of
the Jade platform and provides support for service registry and lookup.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Compiling Relevant Knowledge</title>
      <p>The ideal dispute resolution process is one in which the two parties are better at the
end than they were at the beginning. Unfortunately, not all disputes have this
conclusion. In order to improve this, we believe that it is of ultimate importance to:
(1) provide the parties with more knowledge about the dispute and (2) potentiate the
role of the parties throughout all the process. In fact, parties that have poor access to
important information generally end making bad choices or, at least, they hardly make
the best choice. Moreover, parties usually have a reduced role on the resolution
process, resulting in suspicion about the outcome, mostly because they do not
understand how it was achieved. Thus, in this section we describe the approach
followed in the development of UMCourt in order to attack these problems.
3.1</p>
      <sec id="sec-3-1">
        <title>What Knowledge is Significant?</title>
        <p>
          The first step is thus to identify the knowledge that is meaningful for the parties,
according to the legal domain of the dispute, and then determine the methodologies
suited for compiling that knowledge. On a first instance, it would be interesting for a
party to determine to which extent is it reasonable to engage in a dispute resolution
process. That is, are there significant advantages against a traditional litigation? This
question can be analyzed from several points of view. On the one hand, alternative
dispute resolution processes are generally faster, cheaper, more private and
personalized [
          <xref ref-type="bibr" rid="ref3">3</xref>
          ]. There is however another important factor: the possible outcome
reached through each of the processes. That is, will I reach a better outcome using an
alternative dispute resolution process instead of litigation?
        </p>
        <p>
          It would thus be really important for each party to know its BATNA - Best
Alternative to a Negotiated Agreement, or the possible best outcome “along a
particular path if I try to get my interests satisfied in a way that does not require
negotiation with the other party” [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ]. A party should then understand the notion of a
BATNA and what role it should play in ODR. Doing so will, at least, contribute to the
acknowledgement that an agreement may be disadvantageous [
          <xref ref-type="bibr" rid="ref11">11</xref>
          ]. In fact, the
position of the parties may become much more unclear if they are not foreseeing the
possible results in case the negotiation / mediation fails. “If you are unaware of what
results you could obtain if the negotiations are unsuccessful, you run the risk of
entering into an agreement that you would be better off rejecting or rejecting an
agreement that you would be better off entering into” [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ]. That is to say, the parties,
by determining their BATNA, would on one side become “better protected against
agreements that should be rejected” and, on the other side, they would be in a better
condition to “reach an agreement that better satisfy their interests” [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]. But, besides
that, a BATNA may play additional interesting features for the parties. For instance, it
may be used as a “way to put pressure on the other party”, especially in dispute
resolution procedures allowing the choice of going to court [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ].
        </p>
        <p>
          However, the use of the BATNA alone is not enough to take informed decisions as
parties often tend “to develop an overly optimistic view on their chances in disputes”
[
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]. This may lead parties to calculate unrealistic BATNAs, which will influence
later decisions, leading even to either reject generous offers from the other parties, or
to stand stubbornly fixed in some positions [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]. It is thus important to also consider
the concept of a WATNA, or the Worst Alternative to a Negotiated Agreement [
          <xref ref-type="bibr" rid="ref10 ref14 ref15">10,
14, 15</xref>
          ]. A WATNA intends to estimate the worst possible outcome along a litigation
path. It can be quite relevant in the calculation of the real risks that parties will face in
a judicially determined litigation, imagining the worst possible outcome for the party.
At this point, a party would be aware of the best and worst scenario if the dispute is to
be solved in a court.
        </p>
        <p>
          However, it could also be interesting to consider the whole space between the
BATNA and WATNA as a useful element to be taken into account for making (or
accepting) a proposal. If we consider for instance, in the labor law domain, the
scenario of a worker being fired, litigation will most likely occur. Under many legal
systems, a huge deal of legal parameters have to be considered, including antiquity,
supplementary work, just cause for dismissal, among others. For the worker, the
amounts involved are not irrelevant: being fired without good indemnities may be
seen as a double sacrifice. But he might, on the other side, receive significant
financial compensation. In order to clearly see the advantages of a proposed
agreement, parties should thus also consider the spectrum between their BATNA and
their WATNA. Of course, the less space there is between BATNA and WATNA, the
less dangerous it becomes for the party not to accept the agreement (unless, of course,
their BATNA is really disadvantageous). A wider space between BATNA and
WATNA would usually mean that it can become rather dangerous for the party not to
accept the ODR agreement (except in situations when the WATNA is really not
inconvenient at all for the party). We can thus argue that knowledge about the space
between the BATNA and the WATNA is also very important. This space is evidently
related to the Zone of Possible Agreement proposed by Raiffa (1982) [
          <xref ref-type="bibr" rid="ref16">16</xref>
          ]. It is the
zone where an agreement can be met that is acceptable to both parties.
        </p>
        <p>
          Moreover, it would be interesting for a party to understand the region of this space
in which an outcome is more likely. That is, if the parties are to solve the dispute
through litigation, what is the most likely outcome? In fact, sticking only with the
BATNA and WATNA may not be realistic as these are usually not the most likely
outcomes but merely informative values that establish boundaries. Thus, an informed
party should also consider the MLATNA – Most Likely Alternative to a Negotiated
Agreement [
          <xref ref-type="bibr" rid="ref15">15</xref>
          ]. Using the same arguments, we can also conclude that the existence
of metrics that measure the probability of each possible outcome could also be
extremely useful for a party.
        </p>
        <p>Concluding, in order for a party that is engaging in an alternative dispute resolution
to take informed and rational decisions, he should consider knowledge about: (1) the
best possible outcome in litigation; (2) the worst possible outcome in litigation; (3)
the space between the two previous values; (4) the most likely outcome in litigation
and (5) the probability of each outcome within the zone of possible agreement.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2 Domain-dependent Methods for Compiling Knowledge</title>
        <p>
          Having seen the knowledge that a party should have in order to take rational
decisions, let us now depict the methods for compiling that knowledge. Considering
the BATNA and the WATNA values, we are using a rule-based approach. Rule-based
Systems (RbS) are generally the simplest way of implementing intelligent behaviors
[
          <xref ref-type="bibr" rid="ref17">17</xref>
          ]. Thus, RbS are a way to store, interpret and manipulate knowledge about a given
domain (data and procedures) in the form of IF-THEN rules, in which each rule
defines a small piece of the knowledge. Considering the legal domain, a parallel can
be established as legislations and other legal concepts are built on the concept of rule.
In that sense, one can picture the development of rule-based systems that describe
rules of specific legal fields that can then be used to determine which rules apply in a
given case. Consequently, it is possible to implement rule-based systems that model
specific norms in order to determine the values of the BATNA and the WATNA.
        </p>
        <p>Let us take, as an example, the Portuguese labor law domain, as depicted in Decree
of Law (DL) 7/2009 (Portuguese laws), considering a scenario in which a worker
wants to end the labor contract claiming that the employer did not pay the last three
salaries. According to Article 394th, nr. 2 a), the lack of regular payment of the salary
constitutes a just cause for a worker to end the contract. Moreover, Article 394th, nr. 1
when there is a just cause, the worker can immediately end the labor contract. The
first question is thus to determine the existence or not of the lack of payment, and
thus, of a just cause for ending the contract. Assuming that this has been proved, let us
try to determine the best and worst scenarios, from the point of view of the worker.
The most important norms are found in Article 396th, numbers 1, 3 and 4. Number 1
states that, if Article 394th is true (there is just cause for ending contract), the worker
is entitled to 15 to 45 days of salary plus indemnity for each year of contract. It also
states that this value varies according to the degree of wrongfulness of the employer
and that the total indemnity paid to the worker should not be inferior to three salaries
plus indemnity. However, number 3 states that the indemnity paid can be higher
whenever the worker suffered property damage or other damage, of higher value.
Finally, number 4 states that, in the cases of a temporary employment contract, the
value of the indemnity cannot be smaller than the value of the salaries that would be
received until the end of the contract. We can thus formalize the computation of the
BATNA and WATNA in the form of IF-THEN rules.</p>
        <p>A simplification of the rules that allow the computation of the BATNA and WATNA values
according to the Portuguese labour law. This example code considers only the case in which a
worker ends the contract with a just cause. M_SALARY denotes the monthly salary;
D_SALARY denotes the daily salary; M_REMAINING denotes the months remaining until the
end of the temporary contract; +VARIABLE denotes an unknown value, higher than
VARIABLE.</p>
        <p>Def_Rule 396
if RULE_394 then</p>
        <p>WATNA := 3 * (M_SALARY + SENIORITY)
if TEMPORARY_CONTRACT then
if WATNA &lt; M_REMAINING *(M_SALARY + SENIORITY) then</p>
        <p>WATNA := M_REMAINING *(M_SALARY + SENIORITY)
if WATNA &lt; 15 * (D_SALARY + SENIORITY) then</p>
        <p>WATNA := 15 * (D_SALARY + SENIORITY)
BATNA := 45 * (D_SALARY + SENIORITY)
if BATNA &lt; DAMAGE then</p>
        <p>BATNA := +DAMAGE</p>
        <p>There are some interesting advantages in following a rule-based approach. The
main is that this is a relatively simple way of implementing legal norms, being also
easy to maintain and update. Having defined the values of the BATNA and the
WATNA, it is immediately possible to compute the range of the ZOPA: it is given by
the distance between these two values. More challenging is the determination of the
possible outcomes and its corresponding likeliness.</p>
        <p>
          In this case a purely rule-based approach would not be appropriate as it is
necessary to evaluate a group of cases and categorize them according to their
likeliness. Moreover, a mechanism to select cases according to its similarity is also
obligatory. Therefore, following a case-based approach would be an appropriate
choice [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ].
        </p>
        <p>
          In order to determine the possible cases, their likeliness and the MLATNA,
UMCourt relies on the previously mentioned CBR algorithm. However, as our focus
is merely on compiling information for informing parties rather than suggesting an
outcome for the dispute, only the first stage of the algorithm is relevant [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ]. In this
first stage, the Retrieve one, the algorithm selects a group of cases according to its
relevance for the current case, which is given in terms of the similarity. There are
several techniques for retrieving cases. Unlike database searches that target a specific
value in a record, retrieval of cases from the case base must be equipped with
heuristics that perform partial matches, since in general there is no existing case that
exactly matches the new case [
          <xref ref-type="bibr" rid="ref19">19</xref>
          ]. Moreover, we are not searching for an exact match
but for a group of similar cases.
        </p>
        <p>
          To do it, a hybrid approach is being used that combines a template algorithm with a
nearest neighbor one [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ]. The template retrieval narrows the search space so that the
nearest neighbor algorithm performs quicker. The application of a template retrieval
algorithm is possible as it is possible to know a priori which cases have the possibility
of being similar and which ones do not (e.g. cases that address different norms cannot
be similar). In that sense, template retrieval works much like SQL queries: a set of
cases, that match a pre-selection rule, is retrieved from the database. These rules can
be changed dynamically by the system whenever the results of the pre-selection don’t
match the system parameters. For example: one of the pre-selection rules indicates
that cases should be selected if they address the same norm. However, the system can
consider the norm at several levels: Article, Item or Number. The standard rule is to
look at the Article. However, if too many cases are retrieved, the system is able to
dynamically change this specific rule and retry the query with a more specific one.
        </p>
        <p>In the next step, the nearest neighbor algorithm must only be applied to the set of
pre-selected cases instead of applying it to all the cases in the case memory, a task
that could be very time consuming as the nearest neighbor algorithm has linear
complexity (equation 1).</p>
        <p>In this algorithm, the weights are, at this moment, determined by a law expert,
based on the importance that, according to his experience, each of the components of
the similarity measure has. However, it is our objective that, in the future, the system
changes these values dynamically, looking at past iterations, in an attempt to select
the most appropriate weights for each case.</p>
        <p>The output of this phase of the algorithm is a list of similar cases, ordered
according to their value of similarity with the current case. We only need to add the
main assumption of CBR: if a case is similar to another one, then its conclusion is
also expected to be similar. Based on this, we can look at the solution of the retrieved
case with the higher degree of similarity and assume that it is the most likely solution
to the current case. Likewise, we can look at the region in which the similarity of the
cases is higher and assume that the probable solution lies in that region, i.e., the
MLATNA. Following the same approach, for each case retrieved a value of similarity
is also provided to the user, which will indicate its likeliness to occur.</p>
        <p>At this point, the worker has all the main information that he/she may need in order
to make rational decisions throughout the dispute resolution process. It is possible to
use a visual tool to represent all this information in a single and intuitive graphic that
the party can consult. In Figure 2 a graphic for a fictitious case is presented. Each dot
represents a case, with an associated value of similarity and an utility value, which
represents the indemnity that the worker will receive. The case with the highest value
of similarity is the MLATNA and tells the worker the most likely outcome if he
decides to go into a court. The positions of the BATNA and WATNA are also
represented, depicting the best and worst possible scenarios. The dashed line is given
by a 3rd degree polynomial function and represents an overall view of similarity
versus utility. Looking at this line, the worker can conclude that, if he goes into a
litigation process, according to the known cases, the indemnity will most likely be
between a value of 500 and 650.</p>
        <p>MLATNA</p>
        <p>BATNA </p>
        <p>Combining cases with rules, it was possible to develop a methodology that
compiles all the important information at the outset of the dispute resolution process.
This will, in a first moment, help the disputant party decide if he/she should advance
into litigation or if it would be better to continue with this process. At this point, the
disputant party is able to weight the consequences of his possible decisions, assess its
chances of success, determine its consequences and thus achieve more satisfactory
outcomes.
Let us now depict three case studies in which the techniques depicted in this paper are
being applied, all focusing on the Portuguese legal domain.</p>
      </sec>
      <sec id="sec-3-3">
        <title>4.1 UMCourt Divorce and Heritage’s Share</title>
        <p>
          UMCourt Divorce and Heritage’s Share [
          <xref ref-type="bibr" rid="ref20">20</xref>
          ] addresses property division in two
scenarios: divorce and heritage’s share. It is based on the Adjusted Winner algorithm
(AW) [
          <xref ref-type="bibr" rid="ref21">21</xref>
          ] in order to define the share. This algorithm allows the division of n items
between two parties in conflict. AW uses techniques from the game theory field and
deals with the Nash equilibrium concept. It also makes use of a blind attribution of
points to the items that are being divided by the parties. Each party must distribute a
total of 100 points by the items, designating how much they want it. The points
allocated are then submitted to a mathematical manipulation that determines the
division of the properties by the parties. This process, as it is, may be considered
envy-free because each party receives the items according to the preferences that were
assigned, i.e., they receive the items or the most valuable half (according to the
subjective evaluation), which makes each party feel satisfied and without greed about
what the other party received. Division seems fair because each party receives at least
50% of the intended items. Moreover, each party believes his half of the property is
more valuable than the other half (and subjectively it is in fact).
        </p>
        <p>However, the parties may not be completely honest when assigning the points. As
an example, if one of the parties makes the allocation of points considering the
monetary value of the items, and the other party doesn’t have a notion about the
prices or simply assigns the points according to the preferences (unaware of the bad
intention of the other party), the second party is in disadvantage. In order to address
this fair division problem, considering the monetary perspective, this work introduces
some changes in the AW algorithm: the Adjusted Winner by Value. Therefore, a
component depicting the monetary value of each item, in which the arithmetic
manipulation is performed, was added.</p>
        <p>Although the division presented by AW by Value may be considered fair according
to the preferences and the values of the items, the parties may choose not to accept it
as it was proposed. In order to address this issue, a negotiation mechanism that can
mediate the process and present other alternatives was developed. This mechanism is
supported by the techniques presented in this paper. In that sense, parties can access
other similar cases, know their best and worst scenarios, know the most likely
scenario and thus cooperate in a more rational and realistic way in the negotiation
process.</p>
      </sec>
      <sec id="sec-3-4">
        <title>4.2 UMCourt Commerce</title>
        <p>The legal domain of this case study is the Portuguese consumer law. Because this
domain is a quite wide one, we restricted it to the problematic of buy and sell of
consumer goods and respective warranty contracts. Thus, concrete solutions for the
conflicts arising from the supply of defective goods (embodied mobiles or real estate)
were modeled. Financial services are also considered, as well as the cases in which
there are damages arising out of defective products. Regarding the legal boundaries
established, solutions for conflicts are being modeled as they are depicted in Decree
of Law (DL) 67/2003, as published by DL 84/2008 (Portuguese laws).</p>
        <p>
          Using this system, an unsatisfied buyer can use a web site1 or a mobile application
(Figure 3) in two different ways: for simulating a defect of a product that he intends to
buy of for asking for a solution for a dispute arising out of a defective product already
bought [
          <xref ref-type="bibr" rid="ref22">22</xref>
          ]. For deciding on an outcome, the system relies on rules that model the
necessary legal norms. Thus, in this case, given the clear and relatively simple nature
of these norms, the MLATNA is given by the rules, as well as the BATNA and the
WATNA. However, the buyer has also access to similar cases, provided as mentioned
above, concerning disputes with similar characteristics.
Given the current global crisis, labor disputes are more and more frequent. This case
study deals with the issue of an employer being dismissed or wanting to end a work
contract. Under legal systems such as that of Portugal, a huge deal of legal parameters
need to be considered: (1) the antiquity of the worker in the company, (2)
supplementary work, (3) night work, (4) justified or unjustified absence to work, (5)
the possibility of a “just cause for dismissal” being declared by Court, (6) the
existence (or not) of a valid and legal procedure of dismissal, (7) the possibility of
dismissal being accepted without indemnities or (8) of it being accepted but
accompanied by indemnities that could range from a very low to a very high amount
of money. This, together with a relatively complex legislation on this subject, may
make it difficult for workers to take rational decisions.
1 The UMCourt Commerce site is available at http://tiaracserver.di.uminho.pt/odr
        </p>
        <p>In that sense, the information mentioned above can help workers throughout such
processes. Specifically, a worker can consult past similar cases and know the
likeliness of their solutions in his dispute, know his BATNA and WATNA and know
his MLATNA. Moreover, a multi-party negotiation tool supported by the CBR
mechanism is also available (Figures 4 and 5). The main purpose of this tool is to
support effective negotiation between two or more parties involved in a labor law
dispute. The tool starts by proposing the solution of the MLATNA and the parties
engage in a sequence of turns in which, in each turn, all parties can accept, change,
ignore or refuse the current proposal for solution. In each round, if there is no
consensus, the system will build a solution from the suggestions of the parties (if
possible) or will suggest a solution from a similar case. The process goes on until a
consensus is achieved or the system runs out of suggestions for solutions. In this case
study, not only the party has access to the information described above but can also
use a negotiation tool that will improve the efficacy of the alternative dispute
resolution process.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>Conclusion</title>
      <p>The main idea that is present throughout this paper is that informed parties are in a
better position to take weighted and rational decisions. Concretely, a party should
consider, in a first moment, the usefulness of entering into an alternative dispute
resolution process. In order to take this decision, concepts like the BATNA, WATNA
and MLATNA are of utter importance. Moreover, the party should also be aware of
all the possible outcomes and their likeliness, in order to have a clear picture of all the
possibilities. In this paper we identified the relevant knowledge for taking rational
decisions and pointed out to domain-dependent methods for creating that knowledge.
In a parallel work, we are developing an abstract architecture that implements these
concepts in several legal fields by using ontologies. In this approach, agents are
abstract entities that provide services useful for all the domains addressed. However, a
service is implemented differently in each domain, according to the specificities of the
legislation. In order to implement the services for each specific domain the agents use
domain ontologies, which define how each action should be implemented. This
approach results in simpler architectures in which functionality reuse is maximized.
Acknowledgments. The work described in this paper is included in TIARAC
Telematics and Artificial Intelligence in Alternative Conflict Resolution Project
(PTDC/JUR/71354/2006), which is a research project supported by FCT (Science &amp;
Technology Foundation), Portugal.</p>
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