The Istar Knowledge Server
To connect to Istar click here.
(At present we have some problem with our old hardware, so this link might
not be active. Keep trying. Please let me know what you
think if you connect, or if you are unable to connect. Thank you.
A.B.)
Click here for main Istar home page.
Contents:
Istar is a knowledge based system which will give you advice about a
variety of topics. Which topic it gives you advice about depends on which
knowledge base it is using at the time. The knowledge base is like a CD
while Istar is like the CD player: just as you can select from a number of
CDs to load onto the player, so you can select a number of knowledge bases
to load into Istar.
Knowledge bases come in many types and sizes, but the ones Istar runs are
designed to give you advice about some expert subject. You are asked
perhaps two dozen questions and then some results are given, with some
explanation. A knowledge based system possesses some apparent
intelligence, in that it will normally only ask you questions that are
relevant and suppress irrelevant ones, and as you answer each question the
information you give is acted upon immediately, so that it might steer the
course of questions into a different track, or even stop it altogether.
A number of knowledge based systems exist in offices and laboratories all
over the world, but Istar has a difference: it can be attached to the
internet so that it can be operated from anywhere in the world. (It can
also be run locally on a machine on your desk if you wish.) The main
internet-accessible copy of Istar is currently running at the Information Systems Institute at the
University of Salford, UK, and offers the current demonstration
knowledge bases (which are based on real ones developed at the University):
- Write your own contract for a construction job
- I'm thinking of buying shares: is this a good company to invest in?
- I'm thinking of planting some trees; how should I select them?
- Can I trust the authenticity of internet messages handled by a given
Certification Authority?
Others will be added from time to time.
When you connect to Istar it will give
you a Welcome Page that lists the knowledge
bases currently available together with a brief description of them. You
select the one you want, and Istar loads a copy for you and starts what is
known as an inference session. An inference session is a sequence of
questions and answers, during which time Istar tries to satisfy a 'goal'
(or a list of goals). It does this by working back through an inference
net, of evidence that contributes to belief in the goal.
For instance, to advise you whether to buy shares in a given company (the
goal), Istar needs to find out whether profits are likely to rise, whether
the company is growing, whether the company is well managed, etc. To find
out whether the profits are likely to rise, it needs to find out what the
recent financial history has been like, whether there has been good capital
investment, etc. To find out whether there has been good capital
investment it asks you, the user. You can give a degree of belief rather
than a strict yes/no answer, if you do not have full information.
When it finds some piece of information that cannot be derived from others
it sends it to you as a question on a specially formatted question page. You select the appropriate answer, and Istar
processes that to seek the next appropriate question. On the question page
there are a number of other options, besides selecting an answer, such as
obtain help and explanation of the question, pausing the session, viewing
statistics or setting a timeout limit.
(Normally the timeout limit is ten minutes, so that if you do not answer
within ten minutes then Istar will stop and abandon your inference session.
But you can set the timeout to anything up to an hour if you know you need
to obtain information to a question. For instance, you might wish to
browse the web to find out information about the company you are thinking
of buying shares in.)
After a number of questions, Istar has enough information to come to some
belief about the goal; in this example, a degree of belief about whether it
is advisable to buy shares in this company.
Then it offers you a What Now Page, from
which you have various options, such as viewing the goals, receiving a
document that Istar has generated (currently only used for the Contracts
knowledge base), resuming a paused session, restarting afresh, viewing
statistics, returning to the welcome page or stopping altogether.
Driving Istar is mainly a matter of selecting answers to questions put to
you on a question page. But some pages have
several questions on them, as an HTML form: a form
page: you select the answers then hit the Go button.
At any time you can go back to a previous question (using your browser's
window history) and give a different answer. In this way, it is OK to
change your mind.
To alter the timeout, just click on the timeout you need; Istar shows you
what the current timeout setting is at the bottom of the page.
When you connect to the Istar Knowledge Server from a link like the above, expect the following pages:
- The Welcome Page. This presents you with
a list of knowledge bases offered by the server. Normally it has a brief
list at the start of the page and longer details of each KB further down.
(Sometimes, that is from some hyperlinks designed to give you direct access
to a particular KB, you skip the welcome page.) Click on the name or label
of the KB you wish (either from the brief description or from its heading
in the longer desription and you proceed to ...
- The KB Introduction Page. (Sometimes this
page is missing, so inference starts immediately.) This page provides an
introduction to the KB, such as telling you what type of questions to
expect, how accurate its results are, etc. Whatever the creator of the KB
decides to give you. Click the 'start inference' hyperlink to start the
inference session, and you will receive a sequence of ...
- Question Pages. These pages are presented in
a sequence, each containing a question and a means of answering it. Often,
the means of answering it is to click on a hyperlink for the answer of your
choice. Sometimes, though, you will be asked to enter a value (such as a
number or a string) and then hit the 'OK' or 'Go' button. Often (depending
on whether the KB believes it makes sense) you have the option of entering
'Unknown' as a value; use this when you cannot give an answer. From these
pages you can also pause the inference session, proceeding directly to the
What-Now page, or obtain help. You can also set the TimeOut. Sometimes,
however, in place of the normal question page, you will be presented
instead with ...
- Questions Group Form Pages. This page is
like the question page but has several questions grouped together. Enter a
value for each and hit the 'OK' or 'Go' button. Over to the right hand
side you have the option of obtaining help for each question individually.
- Help Pages. If you have hit a Help hyperlink associated with a
question then you obtain help or explanation of it. This contains several
types of Help (in early days simply labelled as Help 1, Help 2, etc.). The
intention is that, for example, Help 2 explains concepts in the question,
Help 3 explains what happens on certain types of answer, Help 4 gives
references to other material, and so on - all depending on what the
knowledge engineer decided to include. Don't be surprised if many helps
are blank.
- The What-Now Page. This page is
presented after all necessary questions have been asked and answered (end
of session) and also when you hit the Pause hyperlink. It gives you a
number of options: to see results, to obtain a document if any is created
by the KB, to obtain statistics, to resume a paused session, to start a new
session with the same KB, to return to the welcome page, or to stop.
- The Results Page. This gives you a table
of results, which are the values that have been inferred for various goals
in the inference session goal list. Rather crude, but it should be self-
explanatory. You have the option of clicking on each of the goal names and
obtaining a view of what contributed to each goal value.
- The Document. If none is available then you should get a message, or
perhaps a blank page. But some KBs generate a document, for example, one
KB writes a contract for you. The facility is crude at present.
For more details of what to expect, and an understanding of how the server
works, go to How It Works.
This section under construction. If you find a fault or a puzzling thing
then please email me and it
will be added to this section.
Things sometimes go wrong. Istar is still only a beta program, and still
under development. Here is a list of problems you might meet.
- PROBLEM: I selected a knowledge base, answered the first question, but
got straight back to the welcome page. REASON: Istar occasionally times
you out immediately you select a knowledge base; bug being looked at.
REMEDY: Simply reselect the knowledge base.
- PROBLEM: I hit the answer to a question but was returned to the
welcome page. REASON: Istar has timed you out because you took too long to
answer the question. ACTION: Normally you have ten minutes to answer each
question; but you may set this longer if you wish. Each question and
results page offers a selection of timeouts; click one.
- (This seems to happen with my version of AWeb, 3.1, but not with
Netscape nor IE.) PROBLEM: After the first question, only part of the page
appears. REASON: Being investigated. A 'RST' signal is being sent half
way through the message for some reason. ACTION: Use a different browser
for the time being. Let me
know if you get this error, and tell me what browser you were using.
Thanks.
- More to be added as they come in.
If you like the concept of the Istar knowledge server, and would like to
make some of your own knowledge available in this fashion, then email me. There are several options
available:
- If you have expertise in building knowledge based systems, then you
could download Istar, learn to use it
properly, and build your own. It's free (at the moment).
- If you haven't this expertise and would like to gain it, then we have
a module of a Masters Course in which you can learn to use Istar, hands on.
Then you could build your own.
- But, because Istar runs on an Amiga computer, and you do not
wish to obtain one (even though they're very cheap these days), you could
ask us to build the knowledge
base for you. We would have to charge reasonable consultancy rates for
this exercise, but the more you do, the less we would charge you for.
- Where should your knowledge base be run? There is room for a few
extra knowledge bases with particular characteristics on our machine at the
moment.
- Alternatively, you could purchase your own dedicated machine.
Depending on amount of usage expected, a relatively meagre computer might
suffice, costing as little as $1000. Not bad, for making your knowledge
available worldwide!
For details of how to go about creating your own KB once you have Istar, click here.
See general documentation or explanation of how server works.
These pages are only samples, and the exact wording might change from time
to time.
Welcome. You are connected to the Istar Knowledge Server.
It allows you to run knowledge bases over the internet
using your browser. You will then be asked a sequence of questions by
to which you must give a reply, and then a result will be
given.
Please select the knowledge base you wish to start, from the
following list, and you will be presented with the first
question of the sequence. It may take a few seconds, during
which time the KB of your choice is being loaded,
reset and a search is made for the first question.
Disclaimer: All the KBs, and the knowledge contained
within them, is used at your own risk, and WARNING: most of them
are still in development.
- Write your own Contract for a
construction project. A large KB, this will ask you
between 20 and 60 questions about the construction project and
then assemble a draft contract for you.
More details below.
- Tree Species Selection Suppose you
wished to plant a wood or group of trees on some land you own; what trees
should you
plant?
More details below.
- Internet Trust Can I trust a message I
have received? Check out the quality of the CPS
of a Certification Authority, to make your judgement about this.
More details below.
- Shares Advisor Should I buy shares in a
company? Only a demo.
More details below.
- Test KB
More details below.
Details of Knowledge Bases
This sizeable KB will write a draft contract for a
construction project.
It will ask you between 20 and 60 questions about
the construction project and, from
the information given, will select clauses for a contract. It
then orders them intelligently, compiles a contract and displays
it for you. You can then save it and edit it as you wish.
Also you can alter some of the parameters of the project and
see what differences emerge in the final contract.
This is a demonstration version, yet it can often yield useful
or at least interesting and stimulating results.
This KB emerged from the
INCA
project, motivated by a concern that standard forms
of contract are often not suited to the real needs of the
participants, and are often amended inconsistently and lead
to adversarial relationships. This KB is different: embodying
principles of agreement and compiling contracts intelligently
from standard components. It is designed to be used by
both parties working together, discussing the questions
asked. The contracts produced should thus express more
fully the real agreed desires of the parties.
Suppose you wished to plant a
wood or group of trees on some land you own; what trees should you
plant? Normally, it will be a mixture. This KB advises you
what characteristics of tree species are important when deciding
your mix. It asks around two dozen questions and has about
a dozen goal attributes.
This KB emerged from the
GIS/KBS
project, in response to an initiative from the UK
government to encourage landowners etc. to plant more trees.
There is concern that Britain's tree cover is less than 4%.
Can I trust a message I have received? In critical cases, you would only
trust the authenticity of the sender of a message when the sender was a
subscriber to a Certification Authority with a good Certification Practice
Statement (CPS). This KB asks you for information about the CPS and
determines whether there are reasons for not trusting the authenticity of
the message sender. Its main goal is 'Can't Trust', and the more asterisks
the worse it is. With most CPSs it's pretty bad, so look at the sub-goals
to see which of them is bad, and then use your judgement on whether or not
to trust the message. Note: this KB deals only with authenticity of the
sender, not whether they are authorised to do what they say in the message.
This KB - a draft version - could be useful in two ways:
- To let you judge the authenticity of a message by checking the quality
of the sender's CA's CPS
- To help you design your own (internal?) CPS; it will show you many of
the factors that are important to trust in authenticity.
This KB emerged from the EPSRC-funded project Intelligent
Computation of Trust 1997-2001, as an outcome of the first stage. The
second stage of the research is to see how appropriate it would be to
obtain a lot of the information automatically.
Should I buy shares in a company? This KB - purely a demonstration
version and not to be taken seriously - uses bayesian accumulation of
evidence to determine how advisable it would be to buy shares in a
particular company. It asks questions about the company, its management
and the market it is in, and produces a visual indication in the goal
display of how advisable it would be to purchase shares. It also shows the
belief in some of the sub-goals that contribute to the goal so you can see
why it thinks the way it does.
This KB was produced by one of the students on the Master of
Information Technology course at the University of Salford, whose husband
worked in selling shares.
Click here to cancel.
Page created by Istar knowledge server.
This can take any form, and depends on what has been written for the KB.
It has three hyperlinks at the bottom: to start the inference, to stop or
to return to the welcome page. It also allows you to set the TimeOut
Period.
Do you believe the company has been making good capital investments
recently ?
Please indicate your degree of agreement:
-5, -4, (disagree) -3, -2, -1, 0, 1, 2, 3, (agree) 4, 5,
Unknown
HELP. PAUSE (can resume). Stats.
Timeout set at 10 minutes; Set to 1 5 10 20 30 60 minutes.
Please click on one of the above choices
in answer to your question. You will then be taken
to the next page.
Page created by Istar knowledge server.
This page contains several questions in a form.
What are the company's recent financial indicators?
PAUSE (can resume)
Stats.
Timeout set at 10 minutes; Set to 1 5 10 20 30 60 minutes.
Please click on one of the above choices
in answer to your question. You will then be taken
to the next page.
Page created by Istar knowledge server.
The inference session has stopped, and results are available.
What would you like now:
Timeout set at 10 minutes; Set to 1 5 10 20 30 60 minutes.
Page created by Istar knowledge server.
On this page the values of the goals are in a table, values on the
right. A line of asterisks shows a degree or proportion or probability
between 0..1. Other values you might encounter are numbers, boolean YES/NO
etc.
The Goals are:
| GOAL | VALUE |
|
Important that all trees are tolerant of salt spray, or salt in atmosphere
|
|**......|
|
|
Important that all trees are tolerant of general exposure
|
|******..|
|
|
Important that all trees are generally hardy
|
|*****...|
|
|
Important that all trees are important to air pollution
|
|**......|
|
|
Important that trees not susceptible to squirrel damage
|
|**......|
|
|
Important to have trees that are suitable as nurse species
|
|**......|
|
|
Important that all trees can stand waterlogging or flooding
|
|**......|
|
|
Important that all trees are tolerant of excessive drying
|
|*.......|
|
|
Important that all trees are frost hardy
|
|***.....|
|
|
Important that trees can cope with low Nitrogen
|
|*.......|
|
|
Importance of ability to thrive on site's soil
|
|****....|
|
|
Important that all trees selected are native species
|
|****....|
|
|
Associated bird species mix is particularly important
|
|******..|
|
|
Associated insect species must be carefully considered
|
|*****...|
|
|
Important to have good mixture of tree species
|
|*****...|
|
|
Important that taller species allow light penetration
|
|****....|
|
|
Important that trees suitable for coppicing
|
|****....|
|
|
Important to have species suitable as 'standards'
|
|**......|
|
|
Important to have berry bearing species
|
|**......|
|
|
Important to include species that provide low cover
|
|***.....|
|
|
Important to include species with attractive autumn foliage
|
|****....|
|
Page created by Istar knowledge server.
Copyright (c) Andrew
Basden 1999.
Last updated: 11 September 1999 added what to expect etc. 21 September
1999 Added contents and email for comments.