Short: News of Knowledge Based System Builder Author: Andrew@basden.demon.co.uk Uploader: Andrew@basden.demon.co.uk Version: 1.039 Type: biz/misc ISTAR NEWS 30 October 1996 # Version 1.04 is due out soon. See the enclosed 'History' and 'Bugs and Limitations' below. # In Version 1.03 and before some panel titles are wrong. For instance 'Item' on the Relationship Panel. Andrew Basden. HISTORY OF ISTAR VERSION 1.04, November 1996 I am still working on Version 1.04, and plan to release in November. Today is 30 October 1996. # Added the CONTROL Unary Operator. See 'Using Istar'. This allows attributes to be made 'not applicable' if another one is answered with False. # Added facility to switch tracing on in the command line. # The Preferences panel now has KB 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. # 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. # Can now change fonts for the main easel, the user questions and the document. (Note: document facility still not available.) # Resizing of a KB is now possible, but occasionally fragile; see Bugs and Limitations. # 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. LIMITATIONS The current version of Istar has a number of limitations. Some of them include: # Cannot import to KB. # The FIRSTOK inference method (Present Each To User) not yet implemented. # Cannot use the Import-Text yet on items. # Cannot at present delete value names from an attribute type; can only add them. # Certain obscure conversions between value types do not work fully; best to try them out before you use them. e.g. Float to Odds. BUGS This is a list of some bugs you should be aware of. # (1.04: Can cause crash, but avoidable) The resize KB facility can be a bit fragile and can cause a crash in version 1.04. This is because if the KB increases in size it moves in memory and therefore all the pointers into it must all be changed. If you have several panels up that relate to a KB, e.g. attribute details, relationship instance details, item types, etc. and increase the KB size while they are up, then the panel does not realise the KB has moved and when you click its OK button it stores information where the KB used to be. For this reason, before you attempt to resize you should close down all panels except that for the KB itself. I am working on this, and hope to be all clear by launch of 1.04 in November. # (Can be misleading to user) The explanation of a relationship type is only accurate for simple types; the facility is yet to be finalized. Version 1.03 and earlier. # (Harmless Cosmetic) When you change the name of an item, it doesn't redraw with the new name until F1 or next load. Version 1.03 and before. # (Harmless Nuisance) When trying to resize an item using right-shift, you have to place the mouse *exactly* on the edge of the box: hit-vicinity is zero. Otherwise you will start to draw a link or move the box; if that happens then just hit escape. Version 1.03 and before. # (Harmless cosmetic) When you start drawing on the main easel and abort by hitting escape you get a beep-flash. Don't worry: nothing is wrong. Version 1.03 and before. # (Nuisance) Recently I had things like DirOpus loaded, and went to load up three KBs with full size easels. Then tried to 'rid' a KB and nothing happened. Tried to quit and nothing happened. Because I had run out of Chip memory and the small "Is it OK to rid the KB?" panel would not come up! (Chip memory was down to 13k.) But beware: there is no warning, and none can be given because the warning panel will not come up. # (Harmless nuisance) New facility in Version 1.03, Resizing of KBA, doesn't work; it leaves the KBA as it is. # (Harmless nuisance) The Backup button on the KB Area panel (Version 1.03) has no effect. # (Harmless cosmetic nuisance) Renaming the KB Area sometimes leaves rubbish characters at the end. Version 1.03. # (Probably harmless; POSSIBLY FIXED) There's an odd sort of bug when Istar runs up on some machines. It's perfectly OK on the three 1200s that I have tried it on (020 and 030). But when I run it up on my 4000 it comes up with the main easel and the SIT (Select Item Type) panel and all, but won't draw, and won't respond to clicks on the main control panel. Until, that is, I click around on the SIT panel. Sometimes dragging the listview scroll bar around helps, and then clicking to select an item type, sometimes clicking on the 'New' button. Then there is a delay of a few seconds, and everything starts as normal. Strange. But, as I say, on my three 1200s it seems perfectly OK. 9.9.96: I have found a possible cause of this and corrected it, but have yet to try it out. # (Harmless, cosmetic) When you reset an attribute that is in the middle of a network it propagates the unanswered status OK, but does not show this change in status on the easel. So if the Att is e.g. Bayesian and Shown it retains the solid black line. # (Harmless limitation) Various buttons are not operative yet: Clone item type Import text into item You might find others that either flash or do nowt # (Harmless limitation) Conversion Float to Odds does not work. # (Could lead to unexpected results in your KB) When a conversion does not work you do not get any warning of this fact. What happens depends on the type of conversion, but often the result holds the bit pattern of the uncoverted value, which might of course seem like rubbish, or might hold 0. 30 July 1996. # (Cosmetic, harmless; PARTLY FIXED) Version 1.02: A Form item does not space out the value gadgets properly always. Some of them are too tall and overlap others. 2 August 1996. This is being investigated. It has been partly cured (still untidy) in Version 1.03. # (Frustrating but probably harmless) Version 1.03: When you have two KBs active, and go to the Item Type Panel, and hit the Left or Right RelTypes buttons nothing happens. But when you get rid of all but one then the list of RelTypes appears OK. 5 August 1996. This is being investigated. BUGS FIXED BY VERSION 1.03 (Sep 1996) # FIXED. Version 1.02: Never press the three right hand gadgets of the name/meaning bar unless a knowledge base is present. It will probably crash the machine or send it into an infinite loop since they assume one is present. 2 August 1996. This has been corrected in version 1.03. # Version 1.02: When redirecting a link the DAG cycle detection algorithm sometimes says there is a loop when there is not. 2 August 1996. This is being investigated. 12 September 1996: I have found the bug: it occasionally searched from the wrong node. Now it should be OK in Version 1.03. # Version 1.02. It occasionally crashed while linking two items. I have found a bug that could do this, and corrected it. Version 1.03 should be OK. Copyright (c) Andrew Basden, 1996