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- <h2><a name="">
- Demo Shares Evaluator
- </a></h2><!-- -->
-
- This knowledge base helps you decide whether a company's shares are worth
- buying - or would if the <a href= "#kb">knowledge</a> were accurate. It
- was produced as an exercise by one of my MSc students whose husband was a
- shares advisor. I have included it in these example KBs because it is an
- example of use of a KBS in a highly ill-structured area of knowledge.
- Almost everything you will be asked requires you to make a judgement.
- These judgements are then combined through various stages to form a single
- goal: whether you should buy shares in the company. It is aimed at
- companies in information technology sector.
- <p>
-
- <h3><a name="">
- Context
- </a></h3><!-- -->
-
- This is a result of a student exercise in the U.K., on an Information
- Technology course. Only a demo.
-
- <h3><a name="">
- The Questions You will be Asked
- </a></h3><!-- -->
-
- You will be asked about 20 questions, most being degrees of belief (pseudo-
- slider). Most are asked singly, but a few are grouped into a single page.
- There are no help (explanation) pages as yet.
- <p>
- A few of the questions are oddly worded; please be patient.
-
- <h3><a name="">
- The Results
- </a></h3><!-- -->
-
- At the end of the question sequence, you will be presented with a single
- goal value 'Buy It', whose value is shown as a number of asterisks.
- Roughly, 5 or more asterisks mean the shares might be worth buying - or
- would if the <a href= "#kb">knowledge</a> were correct.
- <p>
- <a NAME="explore">
- But why is the share worth, or not worth, buying? What makes it so?</a>
- Click this goal's name (left column of table) and you will be shown four
- antecedent nodes (sub-goals) whose values contribute to 'Buy It'. This
- allows you to see factors that contribute to the belief that the share is
- or is not worth buying. Maybe one of them is low while the others are
- high? If so, does it matter? You can make a judgement about it. Or, you
- can go back another stage and click on these antecedents, to obtain theirs,
- and so on back to the questions you were asked. (An example exploration of
- a different KB can be found in <a href=
- "http://www.basden.demon.co.uk/pgm/Istar/pages/explore.ict.html">
- http://www.basden.demon.co.uk/pgm/Istar/pages/explore.ict.html </a> with
- comments that show you how you might proceed.)
- <p>
- This is a (crude) example of how you can explore knowledge in such a way
- that you can use your judgement to come to a decision. It stimulates you
- to think of factors that you might have overlooked.
-
-
-
- <h3><a name="">
- How the KB Works
- </a></h3><!-- -->
- The KB has a single goal, 'Buy It'. It accumulates evidence from
- antecedent nodes by a process of <a href=
- "http://www.basden.demon.co.uk/pgm/Istar/inference.html#bayes">bayesian
- accumulation of evidence</a>. But, before it can do this, the values of
- those nodes must be obtained. These are obtained in the same way: bayesian
- accumulation from their antecedents, and so on, all the way back to
- questions put to you.
-
- <h3><a name="">
- State of KB
- </a></h3><!-- -->
- Only a Demo.
- <ul>
- <li> Do not trust it - though the <a href= "#explore">exploration cited
- above</a> could be useful even in its present state. First, there are many
- factors missing (I guess; it was after all only a student exercise).
- Second, most of the weights of the links (important in bayesian
- accumulation of evidence) are set to the standard odds-multiplier of 3:1.
- They need to be modified.
- <li> As mentioned above, some pages are poorly worded. You won't
- understand what they are getting at.
- </ul>
-