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- HISTORY OF ISTAR
-
- Plans
-
- I plan, next version, to have a Lists facility which will allow you to form
- lists of items, atts, relationships according to various selection
- criteria, including manual addition, and then to use any list as a goal
- list, and to perform simple relational-database-like operations with lists,
- such as selection, union, intersection, join.
-
- VERSION 1.06, February 1997
-
- # Attribute Details Panel: If you change the value of a Constant
- attribute then it sets the value to answered and propagates it when you hit
- OK. It used not to do this, and that meant that sometimes the new value
- would not take effect immediately.
-
- # Keys. First, you can now show the consequent fan/net as well as the
- antecedent one. Press 'C' over a box for the consequent and 'A' for
- antecedent.
-
- # Keys. Second, it will now show all kinds of relationship in the
- antecedent and consequent fans, not just inference.
-
- # Keys. Third, I've changed the keys used. For two reasons. One is that
- when used on a CD32 with SX32 keyboard there are no keys around the numeric
- keypad and the other is that I could never remember which keys were used.
- So I now use alphabetic keys that bear some resemblance to the action
- needed:
-
- A = Antecedent fan
- C = Consequent fan
- R = Related one step in both directions
- T = To This Type (as before)
- M = minimize or maximize a box size
-
- # Minimize/Maximize box size. A new facility. Some boxes are of little
- intrinsic meaning, merely being minor variants on the meaning of others.
- Often you get a local bunch of antecedents that merely set the value for a
- more important box. So now you can minimize these less important boxes by
- hitting the 'M' key when the mouse is over them. This turns them into
- little squares, quarter of an inch square and with not label - a bunch of
- these starts to look like a bunch of blackcurrants. Their meaning still
- shows, however, and you can do all the normal things to them. Then, if you
- hit 'M' again over a minimized box it expands to its normal size.
-
- # In Attribute Details panel, if att is a Const in derivation and you
- alter the value then it is set to answered. And the result is propagated.
- Because it is assumed that you are altering it for a purpose.
-
- # On using a large KB (ca. 800 boxes and 400 arrows) and a goal list about
- 100 long it took around 3 seconds to reset all the goals on a basic Amiga
- 1200. (Because all the consequent fans of all reset attributes have to be
- traversed.) A noticeable delay, though not unreasonable for a KB of this
- size and complexity. I investigated the time taken (3.3 seconds on basic
- Amiga 1200 and 1.4 seconds on Amiga 1200 with 50MHz 68030) and checked that
- the algorithm was working OK and not doing more work than it need to (it
- was OK). There might be ways of speeding it up slightly. But at present
- it is not high priority; 1.4 seconds delay seems perfectly reasonably for a
- KB this size when the subsequent question sequence is around 40 questions
- long.
-
- # Bug in Chooser was fixed. It now resets attribute to unanswered every
- time.
-
- # Wee Bugfix. When you added an attribute to an item that had an att with
- shown value it didnae do it right - placing the 2nd on top of the first.
- It now does it right.
-
-
- VERSION 1.05, January 1997
-
- # (It's rather nice: The better Istar becomes, the smaller it becomes!)
-
- # Instituted an initial dynamic document facility. You create Document
- items and the document is created dynamically from 'Text Item' items whose
- 'Include' attributes are true. See Item Details Panel. The facility is at
- present very crude, just so you can start to try it out. See the new
- 'Dynamic Documents' file.
-
- # Found bug that stopped Istar being used on the 4000 and 3000 - and
- corrected it.
-
- # You can now add new attributes to existing item instances (you could add
- to item types before, but not instances). e.g. if the standard 'Cat' item
- type has attributes of Name, Has-Whiskers, Colour and Sound-Made, and you
- make instance 'Susie', with attributes: Has-Whiskers = TRUE, Colour = Grey,
- Sound-Made = Miaow, before, that was all you could record about Susie. But
- now you can add any new attributes you like without affecting the item
- type. So you can enter Number-Of-Legs = 3 (she got run over!).
-
- # You can also re-order attributes now in both item types and item
- instances.
-
- # You can now read and write preferences files.
-
- # I went through all the modules with a fine tooth comb, making some
- internal changes (specifically, replacing rbDataAddr() with ikDataAddr(),
- etc.). In particular, some of the old code made the wrong tests after a
- routine returns a C pointer. Took the opportunity to rationalize the error
- handling and error messages.
-
-
- VERSION 1.041, November 1996
-
- # Found a bug had crept into Version 1.04 that prevented changing value
- types in Attributes Details panel. So corrected it.
-
- # Also, internal changes to the way text of labels is displayed.
-
- VERSION 1.04, November 1996
-
- # Added the CONTROL Unary Operator. See 'Using Istar'. This allows
- attributes to be made 'not applicable' if another one is answered with
- False. See new version of 'Using Istar' document.
-
- # Lots of work allowing you to set Preferences ...
-
- # Will now read IstarSys:IstarPrefs, if available, when starting up to set
- various preferences. An IstarPrefs_LowMem is supplied.
-
- # Can now change fonts for the main easel, the user questions and the
- document. (Note: document facility still not available.)
-
- # The Preferences panel now has KB and font information as well as Easel
- info, and it only sets the sizes for new KBs, not the existing one.
- (Scroll amount is set for all KBs and Easels, though.) This makes it
- easier to prepare for a low memory situation.
-
- # Added facility to switch tracing on in the command line.
-
- # Changing the size of a currently displayed Easel is now done from a new
- 'Easel' button on the KB Panel, not from the Preferences panel.
-
- # A wee change: Before, on hitting 'Quit' it would first ask "Do you want
- to quit?" and then ask for each KB "Do you want to get rid of it?" Now it
- asks about all the KBs first, and then "Quit?" This allows you to clear
- out all the KBs but not quit the program, so to start other KBs again.
-
- # A button on KB panel 'See Easel' will bring the easel of that KB to the
- front; useful when you have several KBs up.
-
- # Tidied up all panel handling. Users shouldn't see any difference, but
- it makes a bit smaller.
-
- # New documentation file, KBs, which outlines all manipulation of whole
- knowledge bases, and IstarPrefs file.
-
- # Resizing of a KB is now possible, but occasionally fragile; see Bugs and
- Limitations.
-
- # When saving a KB you can now have automatic backups made of the file:
- see KBs document. The old file is not overwritten, but has date and time
- appended to it.
-
- # Slight improvements to the Explanation of Relationship Instances.
-
-
- VERSION 1.03, September 1996
-
- # Made Istar more usable for drawing semantic networks. Two main
- facilities:
-
- # Added facility to alter the visual appearance of item boxes, in a
- limited way. Pen 1 gives the text colour for the label, Pen 2 and Pattern
- give the appearance of the box outline. This meant new gadgets added to
- the Item Type Panel.
-
- # Added facility to define, for an item type box, which types of
- relationship will be drawn when user starts drawing from left or right
- edge.
-
- # Added KB Area panel, showing some details of the KB area, and allowing
- you to alter some.
-
- # Tidied up the mechanism for handling several KBs. Removed one or two
- bugs that had crept in, such as referring to certain things in KB1 when KB2
- was active.
-
- # Added facility to record the Control Screen Parking position.
-
- # Hopefully more tolerant when it doesn't find the fonts it wants.
-
- # Cured one or two bugs encountered when linking items or moving links.
-
- # Tidied up Preferences (but still too few), and cured the problems that
- happened when setting them without a KB.
-
- # Removed the crash/inf loop when hitting the meaning-bar right hand
- gadgets when there is no KB. (As I never told users about them, this
- should not have been a problem.)
-
-
- VERSION 1.02, July 1996
-
- # Placed on Aminet first as /misc/misc without install script, and then
- with proper install script and updated docs in /biz/misc.
-
- # Istar will now process more than one KB.
-
- # It meant replacing the separate Select Item Type, Select Relationship
- Type and Goal List panels with a single single KB panel. Each knowledge
- base has its own KB panel.
-
- # It also meant some internal changes to the structure of the modules
- management, ES module operations, and other things, which are not described
- here. (They are described in my Logs.)
-
- # I also put the backward and forward chaining on a sounder footing.
- Normally it worked OK but some funnies happened with overridden attributes.
-
- # When resetting an attribute for backward chaining, all its antecedents
- were reset OK, but the other consequents of those were not reset. Now they
- are.
-
- # Implemented facility to define new relationship types. This enables us
- to move towards a semantic net builder.
-
- # Added RANDOM unary operator.
-
- # Proper implementation of limits on ordinals and enums.
-
-
- VERSION 1.01, June 1996
-
- This was the first version released. It was a development of the KBTools
- software that came out of the INCA project, with a year spent on making its
- code more robust and generalized. Istar works fairly well and robustly as
- an inference net builder. But it can only process one KB at a time.
-
- Copyright (c) Andrew Basden, on all the dates shown.
-