|The Second International Conference on Case-Based
Reasoning was held at Brown University in Providence
Rhode Island USA at the end of July 1997. The conference was a clear success and this
report will give you my impressions of the event. I have not included a detailed
description of every presentation, so if you attended and would like to have any of your
impressions added to this report please email them to me.
||Brown University was an excellent venue, and to my
mind shows the clear benefits of using universities to host these conferences. Too many
hotels I have been to think "conference facilities" are the hotel
ballroom, an OHP and a free pen with the hotel's name on. The conference was held in a
high quality lecture theatre with excellent audio video facilities and even an Internet
link for presenters. Accommodation was available on campus whilst more upmarket lodgings
were available in a hotel about 10 minutes walk away. Bars, restaurants, shops and other
attractions were all within an easy walk of the campus.
Leake and Enric Plaza
co-chairs of ICCBR-97
||Praise must go to the conference chairs; if there
were any problems, delegates were not aware of them. The programme committee and reviewers
also did an excellent job. 102 papers were submitted to the conference from 19 countries.
Of these 28 were selected for presentation at the conference with a further 31 presented
as posters. This acceptance rate shows that ICCBR demands a high standard and is crucial
in reporting the development of CBR. Without a journal dedicated to CBR ICCBR is the
premier forum for us to exchange knowledge.
The first day opened with an invited talk by Wolfgang Wilke on
CBR and Electronic Commerce on the World Wide Web. He presented an overview of the work
that the German company tecInno is doing in using CBR for obtaining Internet services.
Demos of these applications are available from tecInno's
web site. Using CBR on the web was a theme of the conference that would be returned to
|There then followed what for me was the best
application paper of the conference by William
Cheetham of GE. The application was the retrieval and adaptation of colour
formulas for plastics. The beauty of this application was people performed it in a clearly
case-based way. The CBR application was able to improve on their performance by being more
objective. Moreover, it used fuzzy logic to perform the similarity assessment clearly
demonstrating that CBR is an approach to problem solving and not a technology per se.
Shimazu of NEC gave a report of NEC's experience of developing CBR
applications. It was interesting to hear that the SQUAD system is no longer being used,
but that because its case-base was held in a proprietary DBMS the case data is still
available to the company. Lessons for us all there. NEC's Help Desk Builder was also
described and Hideo told the conference that he could provide the software to people who
asked for it.
|The first morning concluded with a talk entitled "New Technology Bliss and Pain in a
Large Customer Service Centre" presented by
Helen Thomas of Thompson
Consumer Electronics. This gave a fascinating insight into the difficulties of
successfully fielding a case-based help desk application. The technology is not even half
the problem. People and politics were significant factors in the development of the
systems she described. She talked about the problems of implementing systems to help
"non-technical people solve technical problems for non-technical people"
and she introduced the "mail room test". This involves grabbing a
stranger who is sorting mail from the mail room and asking them to use your CBR system, If
they can, you've succeeded, if not its back to the drawing board!
Rissland enjoying the New England sunshine with Kevin Ashley
||The afternoon had the theme of Issues and Methods for Large-Scale CBR. The first presentation was by Edwina Rissland
about a hybrid CBR and Information Retrieval system called SPIRE. One of the pleasures of
attending and event such as ICCBR is being able to see people, such as Edwina, who have
been so influential in the development of CBR. Edwina is an excellent speaker and the
system she described was very elegant. Details of this work (and more) can be found at the
The Case-Based Reasoning Group's web site at
the University of Massachusetts at Amherst.
Aha introduced a new term to me - conversational CBR (Did you
coin this term David?). This does not describe ICCBR delegates in the bar in the evening,
but describes the iterative process systems such as CBR3 and CaseAdvisor use. David has
featured prominently at both ICCBRs. His extensive knowledge of the ML/CBR literature
keeps presenters on their toes. If you have overlooked an important reference he
may even have a copy on hand to give you! Seriously though, David's thoroughness and
enthusiasm does CBR a great service. His Machine
Learning and Case-Based Reasoning Home Pages provide an excellent web resource. A copy
of David's paper "Refining
Conversational Case Libraries" is
available for downloading.
||David Aha tormenting a grad
student with his lap top and computerised bibliography of ML/CBR research papers
The afternoon was rounded off by a panel discussion
with the topic "Setting a
CBR Research Agenda: Needs from Industry."
This was chaired by Philip Klahr of Inference Corporation and the
David Aha Naval Research
Hideo Shimazu NEC
Ian Watson AI-CBR,
University of Salford
Stefan Wess tecInno
Since I was on the panel I can't really give an idea
of what the audience thought. There was however a deal of agreement between panelists on
issues such as integrating CBR with mainstream DBMS systems, the importance of the web,
and the need to develop simple commercial applications before tackling more challenging
The panel session closed at 5.30 p.m., but this was
not the end of the day. A reception with food and drink was held in the impressive Sayles
Hall where poster presentations were conducted until about 10.00pm. Then (it still being so
early) it was off to a bar with some colleagues. The Trinity Brew House in downtown
Providence was chosen as an interesting example of the US phenomena of micro-breweries
(very small independent breweries). Well, as a connoisseur of English bitter (i.e., I
drink large quantities), I have to say that the Americans have all the proper ingredients
but not the finesse of most English beers. The Hefe wheat beer was very nice though, but
perhaps that's because my palate is not so familiar with this German style of beer.
|Day two opened bright and early (too early for some
of us) with the start of the technical sessions and the broad them of Indexing and Retrieval. From the morning the paper that made the strongest impression on me
was presented by Padraig Cunningham entitled "Using Introspective Learning to Improve Retrieval in
CBR: A Case Study in Air Traffic Control".
There is a specific quality to the work from Trinity College Dublin that I admire and that
I wish more presenters would emulate. What I find when I listen to the Irish CBR people (Mark Keane, Barry Smyth,
Padraig Cunningham, Kathleen Hanney, et al.) is that they have really thought
about what they want the audience to learn from their work. I find when I listen to them
not only do I understand what they have done, but I come away thinking "hey, I
could use that technique". The work presented was about an introspective
feedback mechanism that could optimise local feature weights for a nearest neighbour
||The morning concluded with perhaps
the most talked about presentation of the conference. An invited talk called "CBR and Information Management: Lessons
from the Info Lab" by Kristian
Hammond. Let's be honest; Kristian is an excellent speaker. A rumour circulating
the conference was that he performs stand-up comedy as a hobby. This might well be true as
he certainly made the audience laugh. "Ah....but where was the technical
content" some critics said. Not that he needs any introduction to most of us:
Kristian was a student of Roger Schank and wrote the CHEF system. He now runs the Intelligent Information Lab at the University
of Chicago. In their words "the Info Lab is driven by the desire to not only
develop new ideas, but also to facilitate the transfer of these ideas into working
systems. While the Lab is not concerned with producing applications for the commercial
world, it is focused on the problems of information management that the applied world
faces". The presentation gave us an overview of the work that the Lab is doing
with Web based systems such as FindMe and FAQFinder. Kristian explained that the CBR
community has to move quickly if it is not to be squeezed out of existence by the
Information Retrieval and Database communities. A variety of the systems can be accessed
through the Internet. A recent paper describing case-based knowledge navigation can be
found here. IEEE Expert have recently published a paper on
these systems called "The FindMe Approach to Assisted Browsing" (IEEE
Expert, July/August 1997 pp.32-40).
||Entree is a restaurant agent that
uses it knowledge of cuisine, service and other important features to suggest new
restaurants to users. Taking a restaurant from the user, the system returns with, "If
you liked X you'll love Y."
||A tool which allows a user to
search for information on FAQ lists using a natural language interface.
||Pick A Flick is a video navigator
that is able to find and suggest films based on their similarity to one it already knows
you like. Just as Blockbuster has a section that leads viewers from current hits to other,
similar, films, Pick a Flick notes a user's choices and suggests films that are similar to
Kristian also stated researchers
should find real people with real problems, get data from them and solve the problems. We
should not, he believed, build toy systems with model data. We shall return to this idea
at the end of the conference.
|After lunch it was on to the theme
of Adaptation and an excellent paper presented by Kathleen
Hanney on "The
Adaptation Knowledge Bottleneck: How to Ease it by Learning from Cases." Again a straightforward and clear
presentation from the Irish. Of interest in this work is that it gives primacy to
knowledge in the cases rather than externally engineered rules.
This talk was followed by an interesting demonstration by David Leake et
al. of the idea of using CBR for adaptation. This is the subject that usually brings a
little twinkle to the eyes of researchers who love elegant recursive solutions to
Brigitte Trousse presented
an interesting paper entitled "Using
Case Based Reasoning for Argumentation with Multiple Viewpoints" which can be downloaded here.
Finally Manuela Veloso ended the
session with a case-based planning system that could merge elements of different plans. A
copy of the paper can be downloaded here. What
surprised me was that the adaptation issue did not seem to raise itself as a key
theme (or bone of contention) at this conference as it has at past workshops and
The sessions ended with a Focus
Group meeting: Towards a CBR
Methodology Case-Based Reasoning and Software Engineering organised by Ralph Bergmann,
of the University of Kaiserslautern, and Klaus-Dieter
Althoff, of the Fraunhofer Institute for Experimental Software Engineering. I
did not attend the meeting so will someone else please email me their impressions to include
Finally, the day ended with the
Conference Banquet in the Dining Room of Andrews Hall at Brown. Good food, company and
Californian wine. Some of us then went downtown to look at Providence's Fire-Water
celebration which marks the rebirth of the area around the river. Little bonfires are lit
on rafts on the river and tended to by people in canoes whilst various forms of music are
played along the river bank. After this it was on to the Union Brew House where once again
a Hefe beer got my vote.
|Day three of the conference started
much too early for those of us out on the town until the wee small hours. I'll be honest,
and admit I was feeling distinctly unwell - but I made it to the 9.00 o'clock session!
This was an invited presentation by Angi Voss on Reasoning with Complex Cases based on the findings of the FABEL Project. Angi did an
excellent job of condensing the results of Europe's largest CBR project into about an
hour. Moreover, she was able to make many complex issues understandable. Of the several
talks I have seen from the FABEL project this for me was the best. The underlying issue of
reasoning with complex cases would be returned to later in the day. If you want to learn
more about this subject Friedrich Gebhardt, Angi Voss, Wolfgang Gräther
and Barbara Schmidt-Belz have written a book called Reasoning with Complex Cases
published by Kluwer Academic Publishers. It was agreed by many in the audience that FABEL
has made a major contribution in exploring the boundaries of how we can represent,
retrieve and adapt complex cases. To use Karl Branting's nomenclature,
they have pursued the high road in case representation. It was also noted that
the practical acceptance of such approaches was problematic.
||The next session on Representation and Formalisation relied a little bit too much on slides with
lots of logic on for my taste (given my fragile health that morning).
I do remember that I found Michael Cox's presentation
on "An Explicit
Representation of Reasoning Failures" very clear.
I ended the session by presenting my doctoral student's work (Srinath Perera) on "The Evaluation of a Hierarchical Case
Representation using Context Guided Retrieval." I could of course use my editorial privilege to say how well received
the presentation was--but hey, why not decide for yourself? You can view the presentation here (requires the PowerPoint Animator) and you
can download the paper in postscript format or MS Word97.
We then broke for lunch and a
meeting of the ICCBR-97 programme committee. There were two items on the agenda. The first
was to thank Enric Plaza and David Leake for the
excellent work they did in organising the conference and the second was to decide on the
date and venue for the Third ICCBR conference and on the conference co-chairs. In keeping
with tradition (after two conferences) there will be European and American co-chairs. The
Third ICCBR will be held in Europe and two venues were proposed. England, at Cambridge
University (either St. John's College or Queens College) and Germany, somewhere in Munich.
It was agreed that Karl Branting would be the American co-chair, whilst
the European chair would depend on the venue decision. The Third ICCBR will be held around
the same time as ICCBR-97. The decision will be made by the ICCBR Programme Committee in
September, once they have seen details of the English and German proposals. So if you have
any strong views email either myself,
Michael Richter, or David Leake.
|After lunch the sessions dealt with
Learning & Creative Reasoning. Pietro
Torasso gave an interesting presentation on "A Utility-based Approach to Learning in a Mixed
Case-Based and Model-Based Reasoning Architecture."
Now, be honest, you've been wondering "why is that music playing in the
background?" Well, the piece of music was composed by a CBR system presented in
a paper by Luís Macedo. More information on how CBR can be used to compose music can be
found at the SICOM project page,
along with MIDI samples of the music (play me the CBR
composed tune again).
Marin Simina, a colleague of Janet Koldner,
gave us an insight into how great inventors, such as Alexander Graham Bell innovate. This
paper called "Creative
Design: Reasoning and Understanding" interests me because it proposes a problem solving architecture that
can put seemingly insoluble problems "on the back burner" until a new
(possible analogous) problem suggests a potential solution. This approach seems like it
could be useful for autonomous case-based agents.
This last presentation brought the
conference to a close, except for the Panel and Open Discussion on The Future of CBR. The
Each gave a 5-10 minute
presentation. For those of you who were there, you know that the open session became very
animated, but let's hear from each of the panelists first.
||Ralph Barletta is
Inference's Chief Scientist and formerly implemented ReMind for Cognitive Systems. He was
and still is therefore very influential in the development of CBR tools. He wants to make
CBR part of mainstream software architectures and in particular wants to promote the use
of CBR on the Internet for product selection, product support (call deflection from 800
numbers) and intelligent search by using query cases as in the FindMe Systems. He
also felt that CBR is useful for data mining because it can make the mined data
operational and understandable. Finally, he felt that CBR had a big role to play in
knowledge asset management. (As an aside Ralph is planning for much of ReMind's
functionality to appear in Inference's CBR4 product in the future.)
started by saying that he wanted CBR to be in the next Star Trek movie - by which he means
we will have succeeded when CBR enters the popular consciousness like neural nets have. He
believes that CBR on the web can make CBR more visible to the public. He also maintained
that creating applications for frivolous domains such as choosing a restaurant or a video
makes CBR more intelligible than serious problem domains such as diagnosing faults in
AS7300/S gas turbines. The point being that we need to create demonstrable applications
that solve problems that are common sense to people. The long term goal for him is
autonomous case-based agents.
agreed that CBR is not well established and that even many computer scientists have not
heard of it. He believes though that there is a lack of formalism in our discipline. Many
techniques are used ad hoc and with out a more methodical approach we cannot say why a
certain approach works in one situation and not in another. Too many research papers are
anecdotal - this echoed an observation by David Aha earlier in the week.
CBR is currently an art form and it needs to become an engineering discipline before it
will be taken seriously.
agreed with Michael Richter that we needed to know why CBR worked and why it failed. She
sees CBR as best in hybrid systems so a problem solver can take over when the CBR
component fails to adequately remind (of course this assumes a strong domain theory). She
then went on to explain that the future of CBR lay in complex cases and complex case
representations. If your cases are "little tables of simple values you don't need
CBR, just use C4.5 it will work fine!" (I wish I could do Manuela's accent).
Real cases are complex and features are interrelated; this is where CBR can make its
contribution because "case representation is the science of CBR."
It was about this time that the
panel opened up to the audience and and the debate (argument) kicked off. I don't remember
who started it. However, Manuela, being provocative said "I hate the Web. The
information on it is mostly obsolete." This got Kristian's attention who has
pinned his future on the success of the Web. He stated again that it is innovative and a
good way to get visibility for CBR. The debate then move on to a disagreement between
whether "toy" problems are useful or should researchers use "real"
data for their studies. Manuela and Kristian, now keen to disagree passionately on any
point of principle, took totally opposite views. Manuela stating that toy problems provide
good scientific results in a controlled way whilst applications are not science.
Kristian disagreed stating that toy problems were a waste of time and real findings "only"
came from solving real problems.
In a way I agree with Manuela, since
I have found that research students can be swamped by volumes of real data and are not
able to see the wood for the trees as it were. Also working in a controlled
environment does let one explore the limitations and strengths of an approach better.
However, conversely there is no doubt that not having enough case data also stifles a lot
of research. The availability of case data brought us to the subject of case repositories
(like the UCI ML data sets). David Aha believes that the ML data sets
have stifled creativity, even though he helped create them. It was generally agreed that
the CBR community should not get into benchmarking its techniques in the same way that the
ML community has done, but that there was a role nonetheless for a case-base repository.
(If you are interested AI-CBR is trying to establish a case-archive
to which you can contribute case-bases or links to case-bases).
After this everyone started to agree
with each other (even Manuela and Kristian) and it was agreed that to explain CBR to
people (even other researchers) you had to simplify your applications. This is an
abstraction process that makes the results generalisable and meaningful.
The conference ended with many
people going on to AAAI-97
which had just started "down the hill" and others going on vacation in
New England. I did a bit of both.
See you all at the next ICCBR in
1999 or perhaps sooner at the 3rd. UK CBR Workshop, ECAI-98, or the European CBR Workshop in
Dublin. Please don't forget if you want to add your comments on the conference of link a
downloadable paper please email me.