Automatic invocation of computational resources without user
Contents
1. A US005546502A United States Patent Hart et al Patent Number Date of Patent 5 546 502 Aug 13 1996 11 45 AUTOMATIC INVOCATION OF COMPUTATIONAL RESOURCES WITHOUT USER INTERVENTION 54 75 Inventors Peter Hart Meno Park Calif Jamey Graham San Josc Calif 73 Assignees Ricoh Company Ltd Tokyo Japan Ricoh Corporation Menlo Park Calif 21 22 51 52 58 Appl No 34 458 Filed Mar 19 1993 Int Ch ans G06F 17 20 395 12 395 50 395 60 12 76 395 61 10 13 50 Field of Search References Cited U S PATENT DOCUMENTS 4 954 964 9 1990 Singh 5 263 126 11 1993 Chang FOREIGN PATENT DOCUMENTS 0436459A1 11 1990 European Pat Off GO6F 9 44 WO92 02880 2 1992 WIPO GOOF 9 44 OTHER PUBLICATIONS An Information Retrieval Approach For Automatically Con tructing Software Libraries Maarek et al IEEE Aug 1991 GAMEES II Environment For Building Probabilistic Export Sys Based on Arrays of Bayesian Belief Networks Bellazzi et al 14 17 Jun 1992 56 395 12 395 12 BASE APPLICATION USER INTERACTIONS CONTEXT Elkin P L et al Closing the Loop on Diagnostic Decision Support Systems 14th Annual Symposium on Computer Applications in Medial Care Standards in Medial Informat ics Nov 1990 Washington D2. INFORMATION RETRIEVAL ENVIRONMENT DEVELOPMENT ENVIRONMENT RUNTIME ENVIRONMENT RETURN USER MANUAL INFORMATION RETRIEVE RELEVANT FIG 4 INFORMAT ION BEFORE ADDITION OF SYMPTOM S P F 0 03 OIF Fs Fy Fy Fy FIG 5 AFTER ADDITION OF SYMPTOM S P F 0 03 OF Fs Fy Fy f FIG 6 U S Patent Aug 13 1996 Sheet 5 of 9 5 546 502 SUPPORT GROUP A TOPICS SYMPTOM SYMPTOM B SYMPTOM C TOPICS TOPICS TOPICS TOPIC DATABASE FAULT A TOPICS 45 USER INTERFACE PRIMARY TOPICS SECONDARY TOPICS FIG 7 5 546 502 Sheet 6 of 9 Aug 13 1996 U S Patent 3unsog 44 3m 4 CHILS 4 1517 H3QN31NOO dV 18 08 WOLdNAS JSLVILNVISNI 62 ALISN3G N3A3Nh S QNnOMOXOV8 ALMIQ SS S3NI1 AAVM S 39VWI 1NIVj fS SINIT YOY TVOILN3A S SLOdS xov18 5 LYOddNS W3Q0N31NO2 sav rwv TW 30 LOHSdVNS uH313V 33VI ALISO NIANA S WOLdWAS S3AM3S80 SNOLdNAS Q3A43S80 t 995 samvA rnv TY 30 LOHSdVNS 380338 AVL 39VJ3M31NI 8 914 SSS s S 4s 9555 5 ETT L 10895 dO LYONS 1945 88 LYOddNs H9V3 NIHLIM SOIdOl 193SM31NI 3 18V TIVAV NOLLVIN3WAOOOQ AMVQNO23S NV ANVNIMd 68 5 546 502 Sheet 7 of 9 Aug 13 1996 U S Patent
3. 1 6 go 31815500 6 SH Gui oH MOpDUS puno16y30g 1114 spuog 2018 1 5490 30 sqny 30H Su x 0 g 1J9A 400 Jaddq JM 1104 yunjg ALITVnO 39VMI 9314059311 IRD 06 5 546 502 Sheet 8 of 9 Aug 13 1996 U S Patent OF 2915 jususnipo 3214 K day J0 y3ld spung Yong Ayisuaq uaaauf 440 sq Wd 220 014 10 INWA 300N 2g 1 94 3200 NOLLVIIGNTOOQ INVATIY Jadog quj Ko yung 2 0125 ang 870 AIMO SET 31015500 5 546 502 Sheet 9 of 9 Aug 13 1996 U S Patent FF IId 4212s 1 aod jjo yord 100 al 9089 9 aunpsooud ams A 951 UNI ous E ms sy pup moras 1 9 jjo yoid opi s 6 epis juo ay wojj qeossb joys jaod ou aaoway 1014 apis ay jo 3 ep ay 0 JpjOy ay ap js abaa ay 0 joys juod ay Burysnd ojuj c 0 12045 juod ay g wd joys jaod ay noway 7 9125 v 920 apinb jjo xyoid ay 1N3A30v1d34 Wd 1105019 T E 1X31 VANYA 39IAN3S E spuog 018 uaaaun HO sqny afour afour 2014 aA 3100 120d papyri 140 Ado 5 546 502 1 AUTOMATIC INVOCATION OF COMPUTATI
4. 2 A system as in claim 1 wherein the computational resource comprises a computing system having an informa tion retrieval system 3 A system as in claim 2 wherein the computational resource further comprises a database system 4 A system as in claim 1 wherein the means for operating for the user a base application comprises an expert system 5 A system as in claim 4 wherein the expert system further comprises a belief network 6 A system as in claim 1 wherein the means for receiving into the base application a series of user interactions which establish a context comprises a data entry device 7 A system as in claim 1 wherein the means for instruct ing the computational resource in response to the series of user interactions comprises means for displaying the avail ability of information to the user 8 In a data processing system a method for dynamically generating a result responsive to a series of user interactions comprising the steps of operating a base application and a computational resource external to the base application receiving using the base application the series of user interactions monitoring a context defined by the series of user inter actions dynamically constructing an instruction to the computa tional resource responsive to the context executing using the computational resource the instruc tion to generate a result and displaying the result 9 The method of claim 8 wherein said co
5. C pp 589 593 Morjaria M A et al Modular Reliability Upgrade Option for Copiers or Printers Xerox Disclosure Journal vol 17 No 4 Jul 1992 Aug 1992 Stamford Connecticut pp 231 233 Primary Examiner Allen R MacDonald Assistant Examiner Richemond Dorvil Attorney Agent or Firm Townsend and Townsend and Crew 57 ABSTRACT A system is described for automatically invoking computa tional resources without intervention or request from a uscr of the system In the system a query free information retrieval system is described in which the exact technical documentation contained in existing user or other technical manuals is provided to a user investigating apparatus having a fault The user enters symptoms based upon the user s analysis of the apparatus and in response the system pro vides information concerning likely faults with the appara tus As the symptoms are entered the relative value of individual faults is determined and related to the symptoms they cause The user can then select technical information relating to probable faults in the system 22 Claims 9 Drawing Sheets COMPUTATIONAL RESOURCE D RETURNS RELEVANT INFORMATION 2 PERFORMS SOME ACTION U S Patent Aug 13 1996 Sheet 1 of 9 5 546 502 COMPUTATIONAL RESOURCE BASE APPLICATION USER INTERACTIONS CONTEXT D RETURNS RELEVANT INFORMATION 2 PERFORMS SOME ACTION FIG 1 U S
6. In a data processing system a method for accessing information comprising the steps of Operating a base application that receives a sequence of user inputs operating a computational resource external to the base application monitoring the context defined by the sequence of user inputs to the base application 30 dynamically constructing a query to the computational resource responsive to the context searching with the computational resource using the query for information relevant to the context and displaying information discovered in said searching step 35 18 A method for dynamically invoking a computational resource for a user comprising operating a base application external to the computational resource receiving into the base application a series of user inter actions which establish a context and dynamically instructing in response to the series of user interactions responsive to the context the computa tional resource to perform selected computational 45 Operations 19 A method as in claim 18 wherein said dynamically instructing step comprises instructing a computing system having an information retrieval system 20 A method as in claim 18 wherein said dynamically so instructing step comprises instructing a database system 21 A method as in claim 18 wherein said operating step comprises operating an expert system operating on the computing system 22 method as in claim 21 wherein said operating s
7. before and after snapshot of the entire fault set The after fault snapshot is compared to the before fault snapshot and differences noted by examining which faults were most directly influenced by the new observable In other words those faults which had the strongest reactions to the new observable are determined The support group predicate is based on a AP matrix The AP matrix represents the difference between the probability of each fault before and after a new symptom was entered If the difference is significant enough then there is a correlation between the symptom and the fault a reaction The diagram below defines AP and the resulting matrix The symptoms represented are only those symptoms which are active for the current session These are the only nodes evaluated when measuring the strength of support nonsup port or neutrality at each instantiation F F Fm is the set of all active faults S S 5 is the set of all active symptoms and o support group threshold is the desired threshold For F in F our goal is to find AP where 5 is the latest observed symptom AP P FAS S P FIS 571 5 546 502 9 If AP gt a then ADD S to the F support group SG Preferably we set a 0 01 Matrix Observed Symptoms Si Says oa S F Faults 1 APY Fm FIG 5 is a graph which illustrates the individual prob abilities of a series of faults based upon a set of symptoms entered
8. candidate In effect the user has invoked a query free information database a computational resource without directly requesting such In the preceding example the technician is provided with an interface to an expert s knowledge of copiers as well as technical documentation which supplements the overall capability of the expert system Furthermore the documen tation is provided automatically for the technician without him having to ask the system for additional information The system knows the current context of the diagnoses and simply responds with the appropriate documentation The concept of providing query free information retrieval in any domain is a favorable solution to dealing with query languages natural or otherwise which either fail to fully represent a query goal or fail in their ability to handle complex query statements Our system provides relevant documentation for the current context without the user having to formulate a query and wait for the results To simplify the process of creating node labels used as scarch patterns we take advantage of the structure of the expert system which is usually closely related to the documentation used to describe the domain Thus we benefit from the structure of the expert system by providing contextual pointers to relevant user manual information An expert system typically consists of two major software environments the development and runtime environments During development
9. user manual documentation Whereas most on line informa tion access systems require the user to enter a search query and request processing of that query when searching for relevant information our system does not The availability of relevant information is provided automatically or query free as the user works on a diagnostic problem This is achieved by evaluating the context of the diagnostic session and automatically accessing the appropriate technical docu mentation No time is lost by the user having to stop to search for relevant documentation the documentation is simply waiting to be used Additionally the text provided when it is requested is that of the user manuals text with which the user is already familiar Any updates to the hard copy documentation can be electronically uploaded into our System so the hard copy and electronic copy of the manual are always consistent The actual search and retrieval pro cess does not introduce delays because it is performed off line during development before the user ever uses the system In a preferred embodiment an information retrieval sys tem which employs our invention includes a computing system in which is stored documentation relating to thc apparatus to be investigated as well as probabilistic infor mation relating individual symptoms to faults in the appa ratus which may cause such symptoms The user of the system employs some means of data entry typically a keyboard to s
10. we extract the belief network infor mation such as shown in FIG 2 from the Dxpress devel opment program and process it through an information retrieval system The information retrieval system uses the information from within each node to form a pattern for searching user manual documentation The results of the search are a set of topics which relate to the contents of the node FIG 3 is an example of user manual documentation As shown in FIG 3 a typical user manual includes drawings such as in the upper portion 18 of FIG 3 and text such as in the lower portion 20 of FIG 3 The topical information shown in FIG 3 is used for information retricval as described below Both the drawings and the descriptive text include topics 22 Pointers to the topics 22 then are stored as part of the structure of the node This is performed off line without time delay to the end user Because developers and experts are the only users of the development system they are responsible for conducting the network maintenance manual searches The end user does not have to wait for the system 5 546 502 7 to search for relevant topics 22 because the task has been completed before the runtime system is built This excep tional characteristic means that there is a minimal runtime cost associated with having the information retrieval system coexisting with an expert system which is important because of the complexity of some large knowledge bases FI
11. G d is a diagram illustrating the overall development of our system and represents the system at a high level As shown in FIG 4 the initial step in development of a system according to our invention is the establishment of a belief network The establishment of this network has been dis cussed above in conjunction with FIG 2 Once established the information is transferred to an information retrieval system where relevant topics can be retrieved in the form of user manual information Once that information is identified the complete system is compiled to establish all of the relationships among the faults symptoms and user manuals The resulting runtime environment is then available to a user of this system After establishing pointers from belief network nodes to user manual documentation our system provides an intel ligent method of presenting the documentation at the appro priate time during a diagnostic session For instance if the current expert system context is Drum Damage then we do not want the system to recommend documentation on the Transfer Corona The solution to this problem is to evalu ate what nodes are currently important and only offer their documentation to the user This is described below In the runtime environment the information found by the information retrieval system is made available differently for the symptoms than for the faults As symptoms are entered by a user the documentation found by th
12. ONAL RESOURCES WITHOUT USER INTERVENTION BACKGROUND OF THE INVENTION This invention relates to expert systems and in particular to a system in which computational resources are invoked by a user without direct intervention The increasing use of expert systems as diagnostic tools in service industries has established that knowledge embed ded systems can provide quality expertise within defined domains Most prior systems however do not appreciate the usefulness of technical documentation as a resource for human experts when performing diagnostic tasks On line technical manuals can aid the user by greatly enhancing the potential for success Typical prior art systems which do recognize this asset simply provide interfaces for browsing on line documentation in a help text format This docu mentation however is usually the result of experts and developers rewriting in an abbreviated form the content of technical manuals The exact technical documentation con tained in the manuals and used by most technicians in the field is not provided By rewriting the documentation the experts and developers increase the time to develop a system and decrease the original content Because thc documentation does not rely on the actual manuals which are maintained independently the life cycle costs of main taining this help text documentation is high Some help systems have relied on expert systems to add intelligence to the help s
13. Patent Aug 13 1996 Sheet 2 of 9 5 546 502 FAULTS DRUM SCRATCHED 15 BLADE CLEANER PICK OFF E gt E gt y y SYMPTOMS ED ED FIG 2 U S Patent Aug 13 1996 Sheet 3 of 9 5 546 502 FUSING 22 29 Fusing Unit Removal 22 10 H WARNING The fusing unit is heavy and may be hot be careful when handling the mit 22 Reaoval Remove the fusing unit knob 1 reverse threaded screw A the fusing unit cover B 3 screws Open the top unit and slide the fusing unit all the way out Renove the oil bottle and the oil bottle plate C 2 screws Grasp fusing unit handles front reor D and slide lift out the fusing unit 2 screws loward the front Instollotion T7 22 Fully extend the accuride rails E Align the locating tabs F on the rear of the fusing unit with the locating pins on the accuride roils WARNING If the following step is not done the fusing unit come quay from the copier accidentally possibly causing an injury to the operator 7 Secure the fusing unit to the occuride rails 2 screws CAUTION When installing the fusing unit cover make sure the tab on the inside of the cover lifts up the oil sump stopper J If not the sump will fill and overflow 3 43 FIG 3 U S Patent Aug 13 1996 Sheet 4 of 9 5 546 502 DEVELOP BELIEF NETWORK SUPPLY BELIEF COMPILE COMPLETE SYSTEM NETWORK INFORMATION
14. ation are considered the pri mary objective because an intersection defines a richer description of the current expert system context the con text between that of a diagnostic session in which for instance a symptom and a fault both share a common topic The user likely will find the content of this information more relevant than information describing only individual nodes For example assume a situation exists where there four observed symptoms and five top contender faults The most relevant documentation would be the documentation which connects symptoms and faults for example fault A connected to symptom 2 By defining a support structure which depicts the symptoms and their relative support for contender faults the system determines which symptoms support individual faults Thus it can perform a simple set intersection of the topics from each node in the support structure and produce a rich set of topics with relations to more than one node This set is called the primary topic set We call the set of topics having only a relation to an individual node the secondary topic set To produce a primary topic set for a top contender fault it is necessary to define what it means to be a member of a fault s support group This is done by the support group predicate SGP The support group predicate evaluates each member of the top contender set each time a new symptom is observed This process is very similar to that of taking a
15. e familiar with the documentation and its creation particularly if standard methods of expression are used the experts can provide better descriptive labels for the expert system nodes which in tum become search patterns thus increasing the likelihood of retrieval success Furthermore the actual computationally intensive task of scarching on line text is eliminated from the runtime system by perform ing the action off line during development time These characteristics which provide simple solutions yet exhibit high quality results provide an improved system for infor mation retrieval The above description of the preferred embodiment has been made to explain the invention Although particular examples such as repair of a photocopy machine have been 5 546 502 described it should be appreciated these examples only for illustration and explanation The scope of the invention is defined by the following claims We claim 1 A system for dynamically invoking a computational resource for a user comprising means for operating for the user a base application such that the computational resource is external to the base application means for receiving into the base application a series of user interactions which establish a context and means for in response to the series of user interactions dynamically instructing responsive to the context the computational resource to perform selected computa tional operations
16. e information retrieval system is made available to the user on request For instance if a user enters a symptom into the system and supplemental documentation is available for this symptom an icon appears next to the symptom in the list of observed symptoms denoting the availability of documentation The user may also request to view the documentation of unobserved uninstantiated symptom This is done for instance in cases where the user requires additional infor mation about a symptom prior to instantiation Determining when to provide the supplemental fault documentation is more difficult Faults in the runtime system are presented as a ranked list based on their individual conditional probabilities given all symptoms observed thus far Because the top contenders appear at the top of the list the user is able to distinguish between the real contenders and the low probability faults which have little significance under the current set of circumstances It is for this reason that our system targets only the top contenders to provide automatic documentation for the faults We define an activation predicate AP by which the system decides whether a fault is part of the active set of top contenders The predicate is designed to locate the current set of top fault contenders These contenders can change after each instantiation of new symptoms In the belief network system the combined sum of fault probabili ties is always 1 0 T
17. elect from a menu on a screen to allow the user to enter symptoms concerning the apparatus being investi gated In response the system calculates probabilities of the individual faults as indicated by the symptoms they cause The possible faults are displayed and the user is given an opportunity to select documentation related to the possible faults BRIEF DESCRIPTION OF THE DRAWINGS FIG 1 is a diagram representing the relationship of a computational resource and a base application FIG 2 is a chart illustrating a sample belief network which interrelates faulis and symptoms in a system FIG 3 illustrates typical user manual documentation for example for removal of a fusing unit in a photocopier FIG 4 illustrates the method employed to initially con figure the computer system for the system described herein FIG 5 is a graph illustrate the probability of various faults with the apparatus being investigated before introduction of a new symptom FIG 6 is a chart illustrating the change in probabilities after introduction of a new symptom 5 546 502 3 FIG 7 is a flow chart illustrating the relationship of primary and secondary topics FIG 8 is a chart depicting the process of determining support groups and a top contenders list FIG 9 is a drawing illustrating a typical user interface FIG 10 is a drawing illustrating the selection of primary or secondary information and FIG 11 is a drawing illustrating the dis
18. em uses input from the belief network environment Because the belief network is generated by experts and developers as they construct indi vidual nodes our system provides a controlled input scheme where experts and developers familiar with the technical documentation create the actual English search patterns The developers are also responsible for making use of the table of contents database which consists of all relevant topics from the user manual typically depicted by the original table of contents of the user manual The database is then converted using well known techniques and a natural language understanding system into a semantically defined database where each topic is in the form of a semantic representation enabling searching for semantic similarities The benefits of simplifying how our system is used in this environment are several First our system eliminates the user having to construct a query and the system having to understand it Typically the user of our system never stops to enter a query The appropriate query has already been constructed and parsed and the relevant information retrieved Second our system eliminates the parse failures which commonly occur when users attempt to construct queries directly Our system never has to deal with novel queries because of the control utilized at development time over how to properly construct an input sequence Finally our system simplifies the process of matching
19. es connected to the faults or hypotheses which cause them These network nodes both symptoms and faults provide the content for the 10 25 30 35 45 50 55 65 4 information retrieval system The software we use in the preferred embodiment to achieve this relationship is known as DXpress and is commercially available from Knowledge Industries Palo Alto Calif Although here we use the terms fault and symptom it should be understood they are used solely for explanation Other equivalent terminology may be readily employed for example condition and manifestation state of nature and observation etc The use of fault and symptom is particu larly convenient because in the preferred embodiment our system is used by repair technicians to diagnose and repair apparatus FIG 2 is a diagram illustrating a typical relationship of faults and symptoms For illustration the faults and symp toms chosen relate to a photocopier repair adjustment con text such as might be employed in conjunction with thc system of our invention As shown in FIG 2 each fault can be related to more than one symptom and each symptom to more than one fault For example the fault of a scratched drum 10 can cause many different symptoms including dotted lines 12 Dotted lines however can also be caused by a faulty pick off pawl 15 Of course only a few faults and a few symptoms are shown in FIG 2 An actual belief network will be much la
20. faults the system pro vides only the most relevant textual information of the current context of the diagnostic session All other docu mentation is available for the user to browse through but not recommended by the system We also provide a method of offering more set of documentation for individual active faults by intersecting the topics from the supporting symptoms i e the symptoms which have helped increase an individual fault s likelihood and the fault The result is a set of topics more specific in their depiction of the current diagnosis By exploiting the belief network system at development time we are able to use the content of the network to locate relevant documentation to be offered at runtime At runtime we take advantage of the active nodes and their alliances to provide more relevant documentation at the appropriate stages during a diagnostic session 5 546 502 5 Although other methods can be used we retrieve the appropriate information based on the user manual table of contents method This method is described in detail in commonly assigned copending U S patent application Ser No 07 988 729 entitled Method and Apparatus for Seman tic Pattern Matching for Text Retrieval The table of contents method has several advantages over comparable systems First the table of contents system uses natural language understanding techniques and a unique method of propagating the contex
21. hich is described below The symptoms for the sake of this example are members of a particular fault s support group fault A in the sense of being related to each other as described in conjunction with FIGS 5 and 6 As a result the symptoms intersect 35 to establish primary topics 40 which are likely of most interest to the user Where the symptoms do not so relate to each other as being within a given fault support group secondary topics 42 occur which are less well focused than the primary topics but are still of interest to the user and are available to the user In response to this information the user may employ the user interface 45 to select documentation on the primary or secondary fault A topics 47 available from the topic database 50 FIG 8 is a diagram illustrating how both the activation predicate and the support group predicate fit into the existing runtime environment to provide automatic documentation recommendations In FIG 8 the dark arrows represent flow and the open arrows represent output from the system The figure illustrates how through the user interface 70 a before snapshot 71 is presented of all fault values prior to the entry of the newest symptom 72 In the case of FIG 8 the previous symptoms 74 consist of symptoms S through S which have been observed The probabilistic information for these symptoms is presented in the manner described above 20 30 35 45 55 65 10 Next the
22. hus each time a new symptom is recorded the faults which have a strong relationship with this symptom will increase in likelihood When their values increase other fault values decrease so that all fault prob abilities continue to sum to 1 0 Each fault can have a positive negative or neutral reac tion The positive reaction to the instantiation of a new symptom defines support by the symptom for the fault A negative reaction typically defines non support but may not 15 20 25 30 35 45 55 65 8 take the fault out of contention For most systems the neutral reaction is the most typical reaction because of the number of faults and their association with that symptom the most likely situation is that only a few faults have a significant relationship with an individual symptom Essen tially the activation predicate eliminates irrelevant faults by using a threshold value of 0 03 or other desired value faults having a probability of 0 03 or greater are considered top contenders These contenders are the only faults which will signal the user that documentation is available Of course other criteria could readily be used in place of a fixed threshold Thus far we have discussed providing user manual docu mentation for individual nodes not taking into account possible relationships in the documentation between fault and symptom nodes In fact the nodes which do intersect in the user manual document
23. into our system at a given time Note that the sum of the probabilities of all faults must be 1 0 At the instant of the graph in FIG 5 faults F4 and F are the top two contending faults as being likely to have caused the symp toms entered into the system up to that time FIG 6 illustrates what occurs after an additional symptom S is entered into the system The addition of symptom S increases the probabilities of F and F while decreasing the probabilities of all other faults yet retaining a sum of 1 0 This represents an example of how the AP snapshot method evaluates the results of introduction of a new symptom Notice the increase in probability in faults Fg and F As their value increases the value of the other less relevant faults decreases The AP represents the gap between the previous fault probability value and the value after S has been observed If it is decided that a fault has been influenced either positively or negatively by the new symptom then the symptom becomes a member of the fault s support group After each new symptom instantiation all modified support groups are evaluated producing a new set of primary topics for the user to view in the manner explained below FIG 7 is a chart displaying the operation of our system with respect to primary and secondary topics As shown in FIG 7 symptoms A B and C have been entered 30 These symptoms have been entered through the user interface in a manner w
24. mputational resource comprises an information retrieval system and said step of executing the instruction comprises retrieving an indication of the availability of information 10 The method of claim 9 wherein said step of dynami cally constructing an instruction comprises formulating a query responsive to the context 11 The method of claim 8 wherein said computational resource comprises a database system and said step of executing the instruction comprises accessing a database 12 12 The method of claim 8 wherein operating the base application comprises operating an expert system 13 The method of claim 12 wherein operating the base application further comprises operating a belief network 5 14 The method of claim 12 wherein said computational resource comprises an information retrieval system and said step of executing the instruction comprises retrieving an indication of availability of information 15 The method of claim 14 wherein said step of receiving a series of user interactions com prises receiving entries of symptoms about a condition and said retrieved indication of availability refers to informa 15 tion about the condition 16 The method of claim 15 wherein the expert system includes probabilistic information relating to individual symptoms to the condition which causes those symptoms and wherein said step of executing the instruction further 20 comprises retrieving documentation about the condition 17
25. mputational resources SUMMARY OF THE INVENTION We have developed a system which automatically invokes external computational resources without user intervention In our system a base application typically a computer program is used interactively by an individual As use progresses a variety of internal calculations are performed based upon information entered by the user When these calculations determine that additional information could be 20 25 30 35 45 50 65 2 of benefit to the user based on the information entered then the availability of that additional information is made known to the user If the user desires the additional information it can be displayed for review Alternatively the user can continue with analysis reserving a review of the additional information for later Preferably in our system a belief network is employed to enable probabilistic or other deter minations to be made of the likely importance of the information available In a preferred system according to our invention we employ an information retrieval method which unlike prior systems uses the exact technical documentation contained in the existing user or other technical manuals It does not require the user to know of the existence of information to receive it Furthermore our system does not simply offer on line access to help text but instead provides contextual pointers based on the context of the expert system to the
26. play of on line technical information DESCRIPTION OF THE SPECIFIC EMBODIMENTS FIG 1 is a diagram representing the relationship between a base application and a computational resource in one embodiment of our system The base application typically will consist of an application operating on a computer system for example an expert system a belief network or other computer program The computational resource typi cally will be an information retrieval system a database or other possible provider of useful information or a performer of some function In our system the external computational resources are automatically invoked without specific user intervention Preferably as use of the base application progresses interactively internal calculations are made based upon the input information entered by the user When these calcula tions determine that further information could be of benefit to the user then the availability of that further information is made known In effect the user interactions have estab lished a context by which the computational resource can return relevant information or perform actions Because in the preferred embodiment the availability of the informa tion is only made known to the user as opposed to being displayed to him the user can choose to continue with the analysis or project reserving a review of the information until later Preferably our system functions in the probabilistic expert system en
27. queries and table of contents topics Because the system is well defined in terms of how topics and queries are parsed and repre sented the matching becomes simpler In addition to furnishing the user with query free infor mation retrieval our system provides a method of browsing the user documentation such as the table of contents or 20 35 45 50 55 65 6 relevant subsections Thus the user is equipped with the appropriate tools for locating and using the on line technical documentation As an example of how our system operates the field consider how an expert information retrieval system could be used by a photocopier field service technician A copier technician has connected his laptop computer to a custom er s copier The customer has complained of streaky black lines appearing on all copies made recently The technician loads the copicr diagnostics program and starts to enter by selecting from a menu the known symptoms the copier has displayed As he enters the first few symptoms the system notifies him of the documentation available based upon both the symptoms and the most probable faults The technician immediately pursues the documentation on the leading fault candidate to determine if there is any additional information which may confirm or discount this fault He also views the documentation of an observed symptom knowing that it can be caused by several different faults and not just the leading fault
28. rger than that shown in FIG 2 often including hundreds of faults and symptoms interrelated in a complex arrangement The structure of FIG 2 in the larger system is developed by discussion between the expert and the software devel oper At that time individual probabilities are assigned to the relationships which exist between each individual symptom and all faults For example the expert and software devel oper may decide that when dotted lines 12 occur there is a one third probability that it is due to a faulty pick off pawl 15 and a two thirds probability that it is due to a scratched drum 10 These probabilistic assessments are used in our information retrieval system to identify faults and symp toms and provide resulting documentation to system users During a diagnostic session the user enters observed symptoms into the expert system thus making the symp toms active for the current session a result in a manner described below technical documentation pertaining to these symptoms becomes available for the user to browse through The faults supported by these symptoms that is the faults which cause these symptoms to occur also become active when there is enough justification via the observed symptoms to promote their individual likelihoods When this occurs technical documentation for the individual faults is also made available By recommending only the technical documentation per taining to the active symptoms and
29. s indicated by an icon 95 which the user may select FIG 10 depicts a situation where the user has asked for example by clicking on the box marked text to view the documentation for the Pick off Pawl fault As shown the user is presented with lists of both the primary and second ary topics Once the user has decided which topic to view e g Pick off Pawl Replacement the user interface pro vides a way of browsing from this point of contact That is the relevant topic is simply an entry point into the docu mentation based on a specific content From there the user typically will browse in the surrounding textual or illustra tive areas searching for key information Typical documen tation is shown in FIG 3 FIG 11 illustrates the user interface provided for the user to actively browse through the documentation once a point of entry is established We have discussed an information retrieval system which operates in parallel with a probabilistic expert system providing query free technical documentation as an matic side effect of a diagnostic session The system derives its search goals from the information embedded in the expert system Thus our system takes advantage of an expert s knowledge in two ways as the primary source for constructing a knowledge base and as a provider of con textually sensitive node labels which can later be used to search technical documentation As experts become more and mor
30. t of topics to provide a better search strategy in user manual texts Second our system provides the user with a structured set of fundamental manual topics which relate both to the individual concepts active in the expert system and to the combined context of concepts addressing the same diagnostic goal As a result the content of the information available is richer and more useful to the user Lastly the probabilistic approach provides a natural method of evaluating what is currently important in the system and what observed items support those important concepts Because of this our system offers a more complete and reliable set of documentation to support the current diagnosis Although other types of natural language understanding systems may seem to be better solutions to interfacing with computers other systems have definite limitations which inhibit their overall functionality Such types of natural language understanding technology have not matured enough to be an effective tool in the electronic servicing field where small inexpensive computers are still a requirement The table of contents system upon which we rely provides an interface for entering and searching for relevant infor mation in a user manual domain Of course although we prefer the table of contents approach either type of system could be used in accordance with our invention particularly as the natural language technology advances Our information retrieval syst
31. tep ss further comprises operating a belief network 25
32. user observes the new symptom 77 for example uneven copy density termed symptom S The instantiation 79 of this new symptom is added to the list of observed symptoms 74 and transferred to the activation predicate 80 The activation predicate 80 maintains the contender list 81 of the most likely faults to cause the observed symptoms It also provides an after snapshot 82 of all fault values These values are used by the support group predicate 85 to maintain contender support groups 86 and to intersect the topics 88 within each support group thereby to make primary and secondary documentation 89 available through the user interface FIG 9 is a diagram depicting a preferred embodiment of the user interface of our system The user interface in this embodiment includes three windows 90 91 and 92 one 90 relating to categories of possible findings by the user one 91 relating to the user s observations and one 92 listing the leading fault candidates based upon the probabilities estab lished in the belief network The first window represents the symptoms available in this category for the user to select The middle window 91 represents the observed symptoms In the last window 92 is the list of faults and their current probabilities based on all symptoms entered Also provided are a series of graphical push buttons 94 to enable the user to select other menus or screens where textural or descrip tive information is available that fact i
33. vironment known as belief networks The use of belief networks for assessing one s belief about a set of circumstances is a technique which has gained popularity in the last few years in the field of expert systems The technique represents an expert s knowledge by assigning a conditional probability to the relationship between a symp tom and a fault or more generally between a cause and an effect In such systems by evaluating when or how a symptom occurs with respect to all possible faults which can cause it the expert system can provide a probabilistic assessment of this relationship For example if the relation ship between the symptom streaky copy and the fault toner clutch failure is strong then the likelihood prob ability is high that this fault is present once this symptom is observed In a belief network environment experts and developers assign probabilistic values to the relationship which exists between each individual symptoms and all faults F i e S IF F2 F At runtime these probabilities are inverted using Bayes rule to represent a fault with respect to the symptoms it causes e g P F S 5 Sa Thus as a user observes and enters known symptoms the relative value of the individual faults which are supported by these symptoms goes up eliminating irrelevant faults from the overall diagnosis The structure of the belief network in our system is represented by symptoms or observed featur
34. ystem One such prior art system is described in U S Pat No 5 103 498 entitled Intelligent Help System In that system a monitoring device watches the system user interface and determines what monitoring information to store This information together with the physical state of the system is stored in a knowledge base An inference engine tests rules against the knowledge base data to generate help text Unfortunately in this system the user must request help and that help is supplied as help text A system applied specifically to the medical information field provided a method of automatic information retrieval by evaluating the observed manifestations and possible diagnosis It then provided access to relevant medical texts The system is described in P L Elkin et al Closing the Loop on Diagnostic Decision Support Systems 14th Annual Symposium on Computer Applns in Medical Care Standards in Medical Informatics Washington D C November 1990 IEEE Computer Soc Press Unfortu nately the technical details of the system are still unclear Furthermore in many prior art systems computational resources typically were in a sense turned and off by the user By this we mean that the user decided when to process particular information to determine interrelation ships among all of the entered information In such systems users are unaware of all of the capabilities of the system and thus often overlook valuable co
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