Document Transformations and Information states
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1. allows the instructee to use her hands and eyes for the task itself but it is not an unqualified advantage given that read ing gives much more flexibility than listening to a tape To cash in on the advantages of the aural presentation we need to recapture the flexibility of access that the written medium allows 3 Instructions and Interactivity It is obvious that instructional situations profit from an interactive setting Instruc tional situations are typically situations in which some participants the instructors know a lot that the other participants the instructees need to know to achieve the com mon goals In these kinds of situations it is important that all the required and prefer ably only the required knowledge gets trans ferred at the moment the instructees need it To achieve this it is not enough that the instructor have all the necessary knowledge she needs also to know which state the in structee is in and how that state changes to adapt the transfer of knowledge hence the instructee needs to be able to inform the in structor about his state and influence in this way the course of the interaction Currently we have manuals whose con tent can be presented aurally or in a writ ten form but where both the content and the presentation are uniquely determined a pri ori modulo the speed and order of read ing mentioned above Or we have interac tions that can be at a distance but where a human instru2. dialogue management in the trindi dialogue move engine toolkit NLE Special Issue on Best Practice in Spoken Lan guage Dialogue Systems Engineering Staffan Larsson Alexander Berman Johan Bos Leif Gr nqvist Peter Ljunglof and David Traum 2000 Trindikit 2 0 manual Techni cal Report Deliverable D5 3 Manual Trindi D Traum J Bos R Cooper S Larsson I Lewin C Matheson and M Poesio 1999 A model of dialogue moves and information state revision deliverable D2 1 TRINDI Jan van Kuppevelt 1995 Discourse structure topicality and questioning Journal of Linguis tics 31 109 147
3. the experimental IMDiS we have made several simplifications We have ignored all the natural language generation problems and all the problems related to mak ing text or dialogue natural e g problems re lated to the use of pronouns and other refer ential expressions To handle these we would not only have to discuss basic interactivity but also the medium in which the interaction takes place speech or written text The monologue mode case 1 uses only 2 moves Instruct and Inform Since there is no user to confirm that actions have been performed all actions are automatically con firmed using the update rule autoConfirm RULE autoConfirm CLASS PRE fst SHARED ACTIONS A integrate ETE pop SHARED ACTIONS add SHARED BEL done A The dialogue version cases 2 and 3 uses 9 move types basically the 7 used in GoDiS Ask Answer Inform Repeat RequestRepeat Greet Quit plus in structions Instruct and confirmations Confirm Confirmations are integrated by assuming that the current topmost action in SHARED ACTIONS has been performed as seen in the update rule below RULE integrateUsrConfirm CLASS integrate val SHARED LU SPEAKER usr PRE assoc SHARED LU MOVES confirm false fst SHARED ACTIONS A set_assoc SHARED LU MOVES confirm true EFF pop SHARED ACTIONS add SHARED BEL done A This rule says that if the user performed a Confirm move which has not yet been in
4. Document Transformations and Information States Staffan Larsson Dept of linguistics Goteborg University Sweden sl ling gu se Abstract We discuss ways to explore how instructional material needs to be structured to be presented with var ious degrees of interactivity We use the TRINDI information state approach to model three different degrees of interactivity and present IMDiS a small experimental imple mentation based on the GoDiS dia logue system 1 Introduction Document transformations is becoming a hot topic in industrial research on document cre ation The reason is practical with the new presentation possibilities the advantages of being able to adapt the same document con tent to different uses where the difference can lie in the support devices audiences lan guages or modes of interaction becomes very attractive It not only becomes attractive it also becomes necessary one needs to present material in various contexts oral presenta tions internet portals etc and it is very costly to develop presentations from scratch for these various contexts This situation raises an old question and opens a new area of research can one sep arate content from presentation The philo sophical answer might be no but in practice one doesn t need an absolute answer As this area of research arises more out of practical necessity than pure intellectual curiosity the TRINDI Task Oriented Inst
5. accommodated are different in that case For instance in the example given here the ques tion could something like What should the user I make sure of These questions are valuable to help figure out the discourse struc ture of a monologue They can also be valu able tools to illustrate the differences between dialogue and monologue but they do not give much insight in the effects of various degrees of interactivity Conditionals are treated as follows by the system in dialogue mode When the system has found out what the user s task is it will load the appropriate dialogue plan into the PRIVATE PLAN field of the information state It will then execute the actions in the appro priate order by moving them to the agenda and generating appropriate utterances When a conditional statement is topmost on the plan IMDiS will check whether it has been es tablished that the condition holds by check ing the SHARED BEL field Since the system has previously asked the user and the user has answered either the condition or its negation will be in the set of established propositions If the condition or its negation holds the con ditional will be popped off the plan and re placed by the first or second guarded action respectively DOMAIN MONOLOGUE DIALOGUE precondition P action A if_then C A Instruct A effect E Inform F Instruct check P Inform if_then C A findout P if_then not P Instr
6. action by confirming that the previous action is done and by don t under stand she can indicate that she would want a repetition of what was said immediately before Here we see how to take advantage of the advantages of a different mode of presentation written versus aural we also have to change the type of interactivity S Has the carriage moved from the center position U I didn t understand S Has the carriage moved from the center position Avoid irrelevant information When the action to be taken depends on a condition the system does not give irrelevant informa tion S Has the carriage moved from the center position U yes S The print head is now installed Because there is no feedback from the user a manual has always to give all the possibili ties regardless of which one actually pertains The possibility to ask yes no questions allows us to do away with this redundancy 5 4 More complex task plans In the example above we illustrated how a simple task plan can give rise to a dialogue and a monologue rendering We can get some added flexibility by giving more structure to the task plan For instance in the example above one can argue that the reinstallation proper of the print head is described in point 1 to 2 and that 3 and 4 describe termination secure print_head close top_cover reattach scanner press_and_release yello
7. ate to the agent and that which is shared between the dialogue participants The private part of the information state contains a PLAN field hold ing a dialogue plan i e is a list of dialogue actions that the agent wishes to carry out The plan can be changed during the course of the conversation The AGENDA field on the other hand contains the short term goals or obligations that the agent has i e what the agent is going to do next We have in cluded a field TMP that mirrors the shared fields This field keeps track of shared infor mation that has not yet been grounded i e confirmed as having been understood by the other dialogue participant The SHARED field is divided into four subfields One subfield is a set of propositions which the agent assumes for the sake of the conversation The second subfield is for a stack of questions under dis cussion QUD These are questions that have been raised and are currently under discus sion in the dialogue The ACTIONS field is a stack of domain actions which the user has been instructed to perform but has not yet performed The LU field contains information about the latest utterance To adapt GoDiS to instructional dialogue we added a subfield of SHARED ACTIONS to the shared part of the information state The value of this field is a stack of actions which the system has instructed the user to perform but whose performance has not yet been confirmed by the user In building
8. ctor needs to be available at the time of the action Making humans with the required competence available is expen sive and one would want to achieve some in teractivity without this But computers tend to be frustrating participants in interactive settings when one compares them to human beings and the study of dialogue concentrates mainly on making them as human as possible When one considers the possibility of trans ferring the interactivity from humans to ma chines there are however many intermedi ate possibilities between no interactivity and full blown interactivity in free wheeling di alogue where the participants can ask each other questions about anything and nothing for a more thorough discussion about dia logues between humans and computers see Clark 1999 In this paper we consider how minimal interactions can be modeled on the basis of information which is available in tra ditional instructional manuals In looking at the problem this way one has to keep in mind that instructional man uals although not interactive are coopera tive constructs they assume that they par ticipate with the user in a rational cooper ative task and they are built on an implicit reader model specifically they make assump tions about what the user knows and what she doesn t know and the granularity of the task descriptions that they have to provide They obey in their own way Grice s Maxim of Quantity but they need to leave
9. e post lower print_head push lever close top_cover reattach scanner press_and_release yellow_button yes 7 moved_from_center print_head action complex action plan remove print_head O final state reinstall print_head EFF reinstalled print_head Figure 2 Task plan that this is a conditional plan i e it contains branching conditions From this task plan IMDiS generates two plans a monologue plan and a dialogue plan This is done using the translation schema in Figure 3 The difference between the text plan and the dialogue plan is in the way that condi tionals in the task plan are interpreted In the monologue plan they correspond to sim ply informing the user of the conditional In dialogue mode however the system raises the question whether the condition holds When the system finds out if the condition holds it will instruct the user to execute the appropri ate guarded action Here we can clearly see how dialogue differs from monologue as viewed by Carlson or Van Kuppevelt Carlson 1983 van Kuppevelt 1995 Under these views the writer antici pates the questions the user might have asked but given the user is not present the writer has to make up for the lack of interactivity The questions that can be reconstructed or
10. eds to the next relevant action S put the print head in place U how S Line up the hole in the print head with the green post on the printer carriage U right done S Lower the print head down gently into position U done I remember now pause the print head is put in place S Ok Close the top cover Here however we see the importance of the task structure It is only if we have in formation that gives the structure of the task with subtasks that we can model this Very often instructional manuals will give this sub structure e g in the form of subdivisions of instructions but they tend not to be com pletely consistent in this It is only when this information is given in a consistent way that we can exploit it in a transformation from a written manual presentation to a more inter active presentation 6 Discussion and Research Issues In this experiment we have looked at a few differences that occur in the rendering of the same information under different conditions of interactivity Our little experiment brought out several differences in the rendering of the same task plan as a written text and as a min imally interactive dialogue e Conditionals and preconditions are han dled differently if limited confirmations are possible e The flexibility of access that written text allows needs to be modeled more explic itly in case of aural presentation This can be done minimally by allowing the mac
11. expressions used in the various renderings of the base document One can see this task as akin to that of multilingual genera tion or even simple document rendering Formal ap proaches used for those tasks could be adapted to such an enterprise XML supplemented with stylesheets and schemata could be another possibility References P Bohlin R Cooper E Engdahl and S Larsson 1999 Information states and dialogue move engines In J Alexandersson editor IJCAI 99 Workshop on Knowledge and Reasoning in Practical Dialogue Systems L Carlson 1983 Dialogue Games D Reidel Dordrecht Jennifer Chu Carroll and Michael K Brown 1998 An evidential model for tracking initia tive in collaborative dialogue interactions User Modeling and User Adapted Interaction special issue on Computational Models of Mixed Initia tive Interaction 8 3 4 215 253 H Clark 1999 How do real people communicate with virtual partners Proceedings of AAAI 99 Fall Symposium Pshychological Models of Communication in Collaborative Systems J Ginzburg 1998 Clarifying utterances In J Hulstijn and A Niholt editors Proc of the Twente Workshop on the Formal Seman tics and Pragmatics of Dialogues pages 11 30 Enschede Universiteit Twente Faculteit Infor matica B J Grosz and C L Sidner 1986 Atten tion intention and the structure of discourse 12 3 175 204 Staffan Larsson and David Traum To appear Information state and
12. hine to interpret done or don t un derstand as moves that lead to the pre sentation of the next instruction or to a repetition of the latest instruction Moreover the granularity with which the task plan is represented corresponds to the granularity of the control the user has over the presentations of the instructions In this example we started from an existing manual text Starting from a written manual helped us understand the importance of the informa tion about the task structure This comes of course not as a surprise when the presenta tion mode is fixed as non interactive the the discourse structure can be very flat things need to be done in a certain order whether they are parts of subtasks or not is not rel evant It can be argued that giving more structure will help a user understand better what the instructions achieve but it will not influence the execution directly Material that helps the user understand why she is doing something is typically given in introductory sections and not in the procedures themselves in this type of manual But to make doc ument transformations possible in the sense described in the beginning it is important to clearly separate task plans and assumptions about interactions i e about how the infor mation states get updated Once the task plan is distinguished from the dialogue plan assumptions about the type of interactions between participants can change the dia
13. l it is easy to stop to go back or to consult an other section traditional printed material might be argued to be better in that respect than presentation on a screen we ignore that difference here We can consider this as a limit case of inter activity Note that interactivity does not necessarily imply shared initiative The literature makes a distinction between task and dialogue ini tiative e g Chu Carroll and Brown 1998 but one can have dialogue with both types of initiative staying with one side In the cases we discuss below the task initiative stays com pletely with the manual and the dialogue ini tiative only switches to the instructee in the case where she can indicate that information about some subprocedures can be skipped There is another dimension that often inter venes in discussions about the difference be tween dialogue and written discourse the for mer is spoken the latter is written Given the way things are in a natural setting the writ ten medium tends not to allow interactivity whereas the spoken medium is used mainly in interactive settings Technical changes how ever allow us to separate the written spoken opposition from that between interactive and non or minimally interactive discourse In structional material can be presented in the aural mode without becoming more interac tive e g when a recording is played This can be considered as a plus for instructional ma terial because it
14. logue plan even when the task plan remains constant In practice a completely automatic trans formation of a written manual into even lim ited dialogue is most likely not possible al though one can isolate several linguistic flags for some of the aspects we have been dis cussing e g expressions like make sure that flag preconditions A more realistic approach would be to create a blueprint doc ument that is marked up to allow the deriva tion of several different types of discourse from the beginning on Such an enterprise would need tools such as the TRINDIKIT to model the various cases So far we have only explored one extreme of the monologue dialogue opposition where the interactivity stays very low Obvious ex tensions are to allow the user to ask informa tion that goes beyond the current procedure e g where can i find the piece you mention or how long does this take i have only 1 2 hour here Further inquiry into the possible interactions will help us to define which infor mation is needed and how it needs to be struc tured to fulfill these various needs And of course we will never reach a system in which every user need can be anticipated but then even human beings are not that type of sys tem 4See Grosz and Sidner 1986 for a discussion of the importance of task plans in more explanatory di alogue It would also need tools that make it easy to model the relation between the linguistic
15. ne formal representation of in formation states that has been developed in the TRINDI SDS and INDI projects and implemented in the GoDiS dialogue system Bohlin et al 1999 The central parts of the information state in GoDiS are dialogue plans and Questions Under Discussion QUD a notion borrowed from Ginzburg Ginzburg 1998 SDS Swedish Dialogue Systems NUTEK HSFR Language Technology Project F1472 1997 http www ida liu se nlplab sds 3INDI Information Exchange in Dialogue Riks bankens Jubileumsfond 1997 0134 5 Modeling various degrees of interactivity in TRINDI We envision the following cases e 1 Traditional manual no overt inter action we will consider this as the limit case e 2 Manual can ask yes no questions and understand two types of user responses yes no done don t understand how e 3 User can indicate whether she already knows certain sub procedures 5 1 GoDiS IMDiS information states To model the types of interactions above we started from the GoDiS system which is de signed to deal with information seeking dia logue The IMDiS information state type is shown in Figure 1 PLAN StackSet Action PRIVATE AGENDA Stack Action TMP same as SHARED BEL Set Prop Seiad QUD StackSet Question ACTIONS Stack Action LU Utterance Figure 1 IMDiS information state type The main division in the information state is between information which is priv
16. open a range of possibilities so they need to provide more detail than is necessary in all circum stances In what follows we can only consider cases of over informedness as the information needed to remedy under informedness is not available 4 The TRINDI model The TRINDI project has developed both a framework and a toolkit to model various types of interactions in terms of information state updates The framework whose main ingredients are information states dialogue moves and updates is described in Traum et al 1999 We use the term information state to mean roughly the information stored internally by an agent in this case a dia logue system A dialogue move engine up dates the information state on the basis of observed dialogue moves and selects appropri ate moves to be performed Information state updates are formalised as information state update rules The importance of the frame work is that new interactive hypotheses can be modeled with minor extensions The infor mation state approach is implemented in the TRINDIKIT Larsson et al 2000 Larsson and Traum To appear a toolkit for experi menting with the implementation of informa tion states and dialogue move engines and for building dialogue systems It is used in the experimental implementation described here Various instantiations of the framework articulate further what information states moves and update rules contain In this pa per we use o
17. ruc tional Dialogue EC Project LE4 8314 www ling gu se research projects trindi Annie Zaenen Xerox Research Centre Europe Grenoble Laboratory France Annie Zaenen xrce xerox com engineering is preceding the science and it will take some time before it rest on explicit solid foundations Here we look only at one small aspect of the problem how can we model small changes in presentation that are due to various de grees of interactivity between participants in instructional exchanges We start from a tra ditional manual and make some assumptions about minimal interactivity which are mod eled through dialogue moves We conclude that in this way we can make the presenta tion of the material more flexible An impor tant limit on the flexibility is however the detail with which the discourse structure of the manual encodes the task plan underlying the activity 2 Degrees of Interactivity and the difference between monologue and dialogue We take here the position that the main differ ence between dialogue and monologue is that the former implies interactivity With interac tivity we mean here that the participants can influence each other s moves With respect to the area that interests us here giving in structions to repair devices a traditional writ ten manual influences the user but not vice versa except through notes to the author The user can however influence the order in which she accesses the materia
18. tegrated and A is the most salient action then integrate the move by putting the propo sition done A in the shared beliefs and tak ing A off the action stack Elliptical how questions from the user are interpreted as applying to the currently topmost action in the SHARED ACTIONS stack 5 2 Domain task manuals and dialogues Let s now see how a monologue and a dialogue version of the same task are related Below we have an example from the user manual for the HomeCentre a Xerox MFD e Reinstalling the print head e Caution Make sure that the green carriage lock lever is STILL moved all the way forward before you reinstall the print head e 1 Line up the hole in the print head with the green post on the printer carriage e Lower the print head down gently into position e 2 Gently push the green cartridge lock lever up until it snaps into place e This secures the print head e 3 Close the top cover and reattach the scanner e 4 Press and release the yellow LED button e The printer will prepare the cartridge for print ing e Note If the carriage does not move from the cen ter position after you press the cartridge change button remove and reinstall the print head From this text one can re construct a task plan for reinstalling the print head Such a plan may be represented as in figure 2 Note NAME reinstall print_head PRE moved_forward carriage_lock DEC line_up hol
19. uct achieve P Instruct A findout C if_then C Instruct A Inform F Figure 3 Plan conversion table 5 3 Monologue and Dialogue Behaviour In the monologue mode in IMDiS the control module does not call the input and interpretation modules The text is output move by move as a sequence of utterances from the system S Reinstalling the print head S Make sure that the green carriage lock lever is STILL moved all the way forward before you install the print head S Line up the hole in the print head with the green post on the printer carriage Compared to the monologue mode even a very restricted dialogue mode offers several advantages User attention and control The user can direct her attention to the machine and does not have to look at the manual As we noted in when one goes from written to aural presentation one gains the advantage that the user has free hands and eyes but if nothing more is done this advantage has to be weighted against the disadvantage that the user looses all control over the order and the speed with which the information is presented We can avoid these draw backs by allowing some limited grounding behaviour Very simple interactions like done Confirm or don t understand RequestRepeat give back to the user a limited control over the speed and the order of the presentation at least up to allowing repetition the user decides when to move on to the next
20. w_button yes 7 no moved_from_center print_head y NAME reinstall print_head NAME secure print head PRE moved_forward carriage_lock PRE DEC DEC line_up hole post y lower print_head push lever EFF _ secured print_head remove print_head y action reinstall print_head complex action plan O O final state EFF reinstalled print_head Figure 4 Revised Task Plan conditions To reflect this we can revise the task plan as follows With this structure the user can control the level of detail of the instructions given If the user does not know how to perform a substep she can ask the system for more detailed instructions S put the print head in place U how S Line up the hole in the print head with the green post on the printer carriage U right ok S Lower the print head down gently into position U ok S Gently push the green cartridge lock lever up until it snaps into place U ok S The print head is now securely in place On the other hand if the user already knows how to perform a substep the system moves on to the next step S put the print head in place U done and now S Close the top cover If the user manages to complete the whole action sequence without instructions she can tell the system this and the system proce
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