Conference heron::euro_swas_ai

205.0. "KAPPA versus NEXPERT OBJECT" by GYPSC::BADE () Thu Jun 21 1990 19:31

We have had a chance to look into KAPPA (Intellicorp's new entry level shell)
shortly in order to see how it performs under PCSA. It requires an AT-compatible
PC clocked with at least 10Mhz, running MS-DOS V3.0 and MS-Windows V2.1 upwards.

With a few restrictions and a little patience it even worked on an old 
VAXmate with PCSA V2.1. On an IBM PS/2 (12MHz) running with PCSA V3.0 we could 
hardly see the difference between local and disk server operation. No special 
efforts for tuning have been made.

KAPPA is written in C, but comes closer to LISP-based tools than NEXPERT 
OBJECT for about half of NEXPERT's cost. In addition to rule- class- and 
object editors  it includes an interpreter (KAL) language which makes it more 
similar to EPITOOL. Similar to EPITOOL it includes a window based customizeable
end-user interface with active image objects, which can be dynamically created 
and modified at  runtime(!). Serious drawbacks of KAPPA are the availability 
on just one platform and the lack of facilities for integration (no database 
access support !) and migration.

If an application is likely to stay isolated on separate PCs and doesn't
need further integration or adaptation to special user interface requirements,
KAPPA is a serious competitor for NEXPERT OBJECT. However, whenever the expert
system is likely to grow unpredictedly, in choosing between the two tools we 
would strongly recommend NEXPERT OBJECT.

A tabular comparison between  KAPPA and NEXPERT OBJECT is given below.
Certainly the table is incomplete and just reflects the short timeframe
we had available to look into it.   


Feature					KAPPA		NEXPERT
--------------------------------------------------------------------------------

OBJECTS:

slot inheritence                        yes             yes

local slots                             yes             yes

downwards inheritence			yes		yes

upwards inheritence 			no              yes

multiple parent classes                 no              yes

multiple inheritence                    workaround      yes

subclasses                              yes             yes

subobjects                              no              yes

message passing				yes             workaround

active images                           yes             no

slot options:

     prompting                          yes             yes
     if needed methods                  yes             yes
     before change methods              yes             no
     after change methods               yes             yes
     cardinality (multiple values)      yes             limited
     allowable values                   yes             workaround
     value types: text, number, boolean yes             yes
     value type date                    no              yes
     value type object                  yes             interpretations only

RULES:

symmetry (forward + backward chaining)  yes             yes

dynamic rule creation                   yes             no


INTERPRETER LANGUAGE:                   yes             no

DEVELOPMENT ENVIRONMENT:

rule traceing                           yes             yes

breakpoints                             yes             yes

rule network                            limited         yes

object network                          yes             yes

journalling                             no              yes


INTEGRATION:

call out                                yes             yes

call in                                 no              yes

database access                         no              yes

platforms                               MS-DOS          MS-DOS,VAX/VMS,ULTRIX...

applicable under PCSA                   yes (although   yes
                                        not supported)

knowledge base portability              n.a.            via ASCIIfiles

end user interface                      included with   nxpline only
                                        active images                         
--------------------------------------------------------------------------------
    
    Dirk Bade
    ACT-IS/IT Munich

    It should be mentioned for completeness that KAPPA includes access
    to dBase III, Lotus-1-2-3 and standard text files - all in the MS-DOS
    environment.
    
    Dirk