18 research outputs found
Lessons in Machine Ethics from the Perspective of Two Computational Models of Ethical Reasoning
In this paper, two computational models of ethical
reasoning, one that compares pairs of truth-telling cases and
one that retrieves relevant past cases and principles when
presented with an ethical dilemma, are described and
discussed. Lessons learned from developing and
experimenting with the two systems, as well as challenges
of building programs that reason about ethics, are discussed.
Finally, plans for developing an intelligent tutor for ethics
using one of the computational models as a basis is
presented
Extensionally Defining Principles and Cases in Ethics: an AI model
Principles are abstract rules intended to guide decision-makers in making normative judgments
in domains like the law, politics, and ethics. It is difficult, however, if not impossible to define
principles in an intensional manner so that they may be applied deductively. The problem is the gap
between the abstract, open-textured principles and concrete facts. On the other hand, when expert
decision-makers rationalize their conclusions in specific cases, they often link principles to the
specific facts of the cases. In effect, these expert-defined associations between principles and facts
provide extensional definitions of the principles. The experts operationalize the abstract principles
by linking them to the facts.
This paper discusses research in which the following hypothesis was empirically tested:
extensionally defined principles, as well as cited past cases, can help in predicting the principles
and cases that might be relevant in the analysis of new cases. To investigate this phenomenon
computationally, a large set of professional ethics cases was analyzed and a computational model
called SIROCCO, a system for retrieving principles and past cases, was constructed. Empirical
evidence is presented that the operationalization information contained in extensionally defined
principles can be leveraged to predict the principles and past cases that are relevant to new problem
situations. This is shown through an ablation experiment, comparing SIROCCO to a version of
itself that does not employ operationalization information. Further, it is shown that SIROCCO’s
extensionally defined principles and case citations help it to outperform a full-text retrieval program
that does not employ such information
What's in a Cluster? Automatically Detecting Interesting Interactions in Student E-Discussions
Students in classrooms are starting to use visual argumentation tools
for e-discussions – a form of debate in which contributions are written into
graphical shapes and linked to one another according to whether they, for instance,
support or oppose one another. In order to moderate several simultaneous
e-discussions effectively, teachers must be alerted regarding events of interest.
We focused on the identification of clusters of contributions representing
interaction patterns that are of pedagogical interest (e.g., a student clarifies his
or her opinion and then gets feedback from other students). We designed an algorithm
that takes an example cluster as input and uses inexact graph matching,
text analysis, and machine learning classifiers to search for similar patterns in a
given corpus. The method was evaluated on an annotated dataset of real e-discussions
and was able to detect almost 80% of the annotated clusters while
providing acceptable precision performance
Assessing Relevance With Extensionally Defined Principles and Cases
Expert decision-makers often explain decisions by citing
general principles. In some domains, however, it is nearly
impossible to define principles intensionally so that they
may be applied deductively. After investigating hundreds of
professional ethics case opinions, we hypothesized that the
decision-makers’ explanations extensionally defined
principles over time, in effect, operationalizing them. To
model this phenomenon computationally, we constructed
SIROCCO, a system for retrieving principles and past cases.
This paper presents empirical evidence that
operationalization information can be leveraged to predict
relevant principles and past cases more accurately than
competing approaches that do not use such information
Helping a CBR Program Know What it Knows
Case-based reasoning systems need to know the limitations of their
expertise. Having found the known source cases most relevant to a target
problem, they must assess whether those cases are similar enough to the
problem to warrant venturing advice. In experimenting with SIROCCO, a twostage
case-based retrieval program that uses structural mapping to analyze and
provide advice on engineering ethics cases, we concluded that it would
sometimes be better for the program to admit that it lacks the knowledge to
suggest relevant codes and past source cases. We identified and encoded three
strategic metarules to help it decide. The metarules leverage incrementally
deeper knowledge about SIROCCO's matching algorithm to help the program
"know what it knows." Experiments demonstrate that the metarules can
improve the program's overall advice-giving performance
An AI Investigation of Citation's Epistemological Role
This paper describes how we used an AI model for retrieving
ethics cases to investigate empirically the epistemological
contributions of a decision-makers' citing cases and code
provisions in justifying decisions. In practical ethics, like
law, it is impossible to define abstract principles intensionally
so that they may be applied deductively. After investigating
hundreds of professional ethics case opinions, we
hypothesized that the decision-makers’ explanations
extensionally defined principles over time, in effect,
operationalizing them. We constructed SIROCCO, a system for
retrieving principles and past ethics cases. We used this
computational model to conduct an ablation experiment
concerning a core set of operationalization techniques. This
paper presents empirical evidence that the operationalization
information supports predictions of the relevant principles and
past cases more accurately than competing approaches that do
not use such information
Toward Tutoring Help Seeking; Applying Cognitive Modeling to Meta-Cognitive Skills
The goal of our research is to investigate whether a Cognitive
Tutor can be made more effective by extending it to help students acquire
help-seeking skills. We present a preliminary model of help-seeking behavior
that will provide the basis for a Help-Seeking Tutor Agent. The model,
implemented by 57 production rules, captures both productive and unproductive
help-seeking behavior. As a first test of the model’s efficacy, we used it
off-line to evaluate students’ help-seeking behavior in an existing data set
of student-tutor interactions, We found that 72% of all student actions represented
unproductive help-seeking behavior. Consistent with some of our
earlier work (Aleven & Koedinger, 2000) we found a proliferation of hint
abuse (e.g., using hints to find answers rather than trying to understand). We
also found that students frequently avoided using help when it was likely to
be of benefit and often acted in a quick, possibly undeliberate manner. Students’
help-seeking behavior accounted for as much variance in their learning
gains as their performance at the cognitive level (i.e., the errors that
they made with the tutor). These findings indicate that the help-seeking
model needs to be adjusted, but they also underscore the importance of the
educational need that the Help-Seeking Tutor Agent aims to address
The Cognitive Tutor Authoring Tools (CTAT): Preliminary Evaluation of Efficiency Gains
Intelligent Tutoring Systems have been shown to be effective in a
number of domains, but they remain hard to build, with estimates of 200-300
hours of development per hour of instruction. Two goals of the Cognitive Tutor
Authoring Tools (CTAT) project are to (a) make tutor development more
efficient for both programmers and non-programmers and (b) produce scientific
evidence indicating which tool features lead to improved efficiency. CTAT
supports development of two types of tutors, Cognitive Tutors and Example-
Tracing Tutors, which represent different trade-offs in terms of ease of
authoring and generality. In preliminary small-scale controlled experiments
involving basic Cognitive Tutor development tasks, we found efficiency gains
due to CTAT of 1.4 to 2 times faster. We expect that continued development of
CTAT, informed by repeated evaluations involving increasingly complex
authoring tasks, will lead to further efficiency gains
Opening the Door to Non-Programmers: Authoring Intelligent Tutor Behavior by Demonstration
Intelligent tutoring systems are quite difficult and time intensive
to develop. In this paper, we describe a method and set of software
tools that ease the process of cognitive task analysis and tutor development
by allowing the author to demonstrate, instead of programming, the behavior
of an intelligent tutor. We focus on the subset of our tools that allow
authors to create “Pseudo Tutors” that exhibit the behavior of intelligent tutors
without requiring AI programming. Authors build user interfaces by direct
manipulation and then use a Behavior Recorder tool to demonstrate alternative
correct and incorrect actions. The resulting behavior graph is annotated
with instructional messages and knowledge labels. We present some
preliminary evidence of the effectiveness of this approach, both in terms of
reduced development time and learning outcome. Pseudo Tutors have now
been built for economics, analytic logic, mathematics, and language learning.
Our data supports an estimate of about 25:1 ratio of development time
to instruction time for Pseudo Tutors, which compares favorably to the
200:1 estimate for Intelligent Tutors, though we acknowledge and discuss
limitations of such estimates
Creating Cognitive Tutors for Collaborative Learning: Steps Toward Realization
Our long-term research goal is to provide cognitive tutoring of collaboration within a
collaborative software environment. This is a challenging goal, as intelligent tutors have traditionally
focused on cognitive skills, rather than on the skills necessary to collaborate successfully. In this paper, we
describe progress we have made toward this goal. Our first step was to devise a process known as
bootstrapping novice data (BND), in which student problem-solving actions are collected and used to
begin the development of a tutor. Next, we implemented BND by integrating a collaborative software
tool, Cool Modes, with software designed to develop cognitive tutors (i.e., the Cognitive Tutor Authoring
Tools, or CTAT). Our initial implementation of BND provides a means to directly capture data as a
foundation for a collaboration tutor but does not yet fully support tutoring. Our next step was to perform
two exploratory studies in which dyads of students used our integrated BND software to collaborate in
solving modelling tasks. The data collected from these studies led us to identify five dimensions of
collaborative and problem-solving behavior that point to the need for abstraction of student actions to
better recognize, analyze, and provide feedback on collaboration. We also interviewed a domain expert
who provided evidence for the advantage of bootstrapping over manual creation of a collaboration tutor.
We discuss plans to use these analyses to inform and extend our tools so that we can eventually reach our
goal of tutoring collaboration