DIT++ Taxonomy of Dialogue Acts

(Release 5, May 2010)

The taxonomy ..... Concept definitions ..... Annotation guidelines ..... Annotated examples ..... ISO standard 24617-2 Publications


The DIT++ taxonomy is a comprehensive, application-independent system for the analysis of human and human-machine dialogue and for annotating dialogue with information about the communicative acts that are performed by dialogue segments. The DIT++ taxonomy was constructed by extending the taxonomy of Dynamic Interpretation Theory (DIT), originally developed for information dialogues (Bunt, 1994), with a number of dialogue act types from DAMSL (Allen & Core, 1997) and other schemas. Release 5 has been developed in tandem with the definition of ISO standard 24617-2 for dialogue act annotation. In particular, the definitions of the communicative functions in the DIT++ taxonomy and those included in the ISO standard have been made identical. DIT++ release 5 is thus a fully ISO-compatible annotation scheme, which is somewhat more fine-grained than the ISO scheme; where the latter includes 56 communicative functions, the DIT++ scheme contains 88 functions (including notably more detailed feedback functions and functions for contact management). The XML-based annotation language DiAML (Dialogue Act Markup Language), defined as part of the ISO standard, can therefore also be used for representing DIT++ annotations (see the annotated examples).

The DIT++ taxonomy forms a multidimensional system not only in the sense that it supports the assignment of multiple communicative functions to dialogue segments, but also in the sense that dimensions have a well-defined conceptual status in dialogue analysis, as different aspects of communication that may be addressed independent of each other (see Bunt, 2006). Applied to annotation, the multidimensionality of the schema means that a functionally relevant segment of dialogue behaviour may be tagged as having more than one communicative function -- though maximally one in each dimension, if the tagging of entailed functions is avoided (since it is redundant). In the taxonomy, dimensions are represented in boldface italic.

Some communicative functions can only be used in a particular dimension. For example, Turn Take and Turn Release are two function which can only be used for turn management, and Stalling and Pausing are two functions that can only be used for Time Management. Such functions are called dimension-specific. Other functions can be used in any dimension, for instance a Request can be related to the performance of the task that motivates the dialogue, but it can also be used for time management (Could you give me just a few minutes to consult with Peter?) or for feedback (Could you please clarify that?); such functions are called general-purpose communicative functions. The DIT++ taxonomy thus consists of two parts: (A) that of the general-purpose functions and (B) that of the dimension-specific functions.
In the presentation of the DIT++ communicative functions below, first the general-purpose functions are shown and subsequently the dimension-specific functions.
For convenience, the taxonomy is structured not only in dimensions but also in some additional groupings that do not have a theoretical significane, but that are convenient for seeing the structure of the set of communicative functions, as well for referring to certain groups of functions. Such groupings are represented in italics.

This document consists of five parts:

  • Part 1 shows the taxonomy of communicative functions, beginning with the general-purpose functions. The hierarchical relations in the taxonomy, indicated by indentation, represent relative degrees of specificity of dialogue acts, in the sense that a more specific act has stronger preconditions than a less specific act (which dominates it in the taxonomy); in other words, the preconditions of more specific dialogue act logically entail those of any dominating act in the hierarchy. A communicative function inherits all the preconditions of its ancestors in the hierarchy. For instance, a Check Question is more specific than a Propositional Question because it has an additional precondition, concerning the speaker's expectation of the answer. Similarly, a Confirm(ation) is more specific than a Propositional Answer. This is reflected in the taxonomy by Check Question being dominated by Propositional Question, and Confirm by Propositional Answer.

  • Part 2 contains the definitions of all the communicative functions; you can consult the definition of a communicative function by clicking on its name in the taxonomy.

  • Part 3 gives some examples (not yet updated for release 4) of the linguistic and/or nonverbal expression of these functions; to see examples, click on a definition.

  • Part 4 contains brief set of guidelines for how to use the taxonomy in the annotation of a dialogue.

  • Part 5 contains a list of publications relating to the DIT++ taxonomy or to the underlying theory (DIT).

    The concepts from the DIT++ taxonomy have been applied and evaluated in a number of annotation efforts, in the design of the LIRICS annotation scheme (in the European eContent project LIRICS), and in the design of an ISO standard for dialogue act annotation.

    For some of its application to annotation, see Geertzen and Bunt (2006), Petukhova and Bunt (2007), and Geertzen et al. (2007).

    Another application is in the design of a dialogue manager module that is capable of generating multifunctional contributions to a dialogue; see Keizer and Bunt, 2006 and Keizer and Bunt, 2007.

    For the use of the DIT++ taxonomy and DIT more generally in other studies of dialogue see: Jeroen Geertzen's PhD thesis "Dialogue act recognition and prediction" (February 2009) and Roser Morante's PhD thesis "Meaning in interaction" (November 2007) and the publications listed in Part 5 of this document.

    What's new in release 5:

    Differences between release 5 and the previous release 4 (from February 2010) are described here. Most importantly, release 5 has been developed in tandem with the definition of ISO standard 24617-2 for dialogue act annotation. In particular, the definitions of the communicative functions in the DIT++ taxonomy and those included in the ISO standard have been made identical. Since the latter form a subset of the former, DIT++ release 5is a fully ISO-compatible dialogue act annotation scheme which is somewhat more fine-grained than the ISO scheme.

    An important technical difference between release 5 and release 4 is the introduction of qualifiers, which can be attached to communicative functions and which make these functions more specific. The following three classes of qualifiers have been introduced (for motivation and further discussion see Petukhova & Bunt, 2010; for their semantics see Bunt, 2011):
    Another important difference is the introduction of rhetorical relations between dialogue acts. For example, when a dialogue participant has answered a question he may subsequently think that his answer was not very clear, and give an explanation of what he meant. In previous releases of DIT++, this would be considered as a dialogue act with an Explanation function, which was a specialization of the Inform function. In the new release, this is considered as an Inform act which has the rhetorical relation Explanation to the Answer act which it explains.



    DIT++ Taxonomy of Communicative Functions

  • General-Purpose Communicative Functions
  • Dimension-Specific Communicative Functions

    Examples of DIT++ dialogue acts

    Sources:

    'LIRICS' = from LIRICS project multilingual test suite of dialogues (in English, Dutch, and Italian);
    'DIAMOND' = from DIAMOND project corpus of dialogues (in Dutch);
    'IMIX' = from IMIX project corpus of dialogues (in Dutch);
    'AMI' = from AMI project corpus of dialogues (in English)
    'SCHISMA' = from SCHISMA project corpus of dialogues (in Dutch);
    'OVIS" = from OVIS project corpus of dialogues (in Dutch).
  • General-Purpose Communicative Functions
  • Action-discussion function
  • Feedback Elicitation acts:
  • Partner Communication Management acts
  • Own Communication Management acts
  • Time management acts
  • Discourse structure management acts:
    annotated examples
    -


    ISO dialogue act annotation standard 24617-2 (DIS)

    ISO 24617-2 is an ISO international standard for the annotation of dialogue with dialogue act information. The technical content of the standard was formally approved (by the national standardization bodies participating in ISO), and the official registration of the standard occurred on 4 September 2012 when the document which describes the standard was published by the ISO Central Secretariat in Geneva. A pre-final version of the document describing the standard can be found here; the final version can be obtained from ISO and from the national standardization institutes.

    The ISO scheme for dialogue act annotation is a subset of release 5 of the DIT++ scheme, or rather, release 5 of the DIT++ annotation scheme is an extension of the scheme described in the ISO standard. The DIT++ annotation scheme can thus be said to be strictly ISO-compatible, and in some respects more fine-grained.

    The project team that has developed this standard consists of: Jan Alexandersson, Harry Bunt (project leader), Jean Carletta, Jae-Woong Choe, Alex Chengyu Fang, Koiti Hasida, Volha Petukhova, Andrei Popescu-Belis, Claudia Soria, and David Traum.

    The project team was supported by a group of expert consultants, consisting of: James Allen, Jens Allwood, Nick Campbell, Roberta Catizone, Thierry Declerck, Anna Esposito, Raquel Fernandez, Giacomo Ferrari, Gil Francopoulo, Dirk Heylen, Julia Hirschberg, Kristiina Jokinen, Maciej Karpinski, Staffan Larsson, Kiyong Lee, Oliver Lemon, Carlos Martinez-Hinarejos, Paul Mc Kevitt, Michael McTear, David Novick, Tim Paek, Patrizia Paggio, Catherine Pelachaud, Massimo Poesio, German Rigau, Laurent Romary, Nicla Rossini, Milan Rusko, Candice Sidner, Pavel Smrz, Marieke van Erp, Ielka van der Sluis, Kristinn Thorisson, Aesoon Yoon, Yorick Wilks.

    See also the following papers which summarize the standard very briefly:
    Harry Bunt, Jan Alexandersson, Jean Carletta, Jae-Woong Choe, Alex Chengyu Fang, Koiti Hasida, Kiyong Lee, Volha Petukhova, Andrei Popescu-Belis, Laurent Romary, Claudia Soria, and David Traum:
    "Towards an ISO standard for dialogue act annotation". In Proceedings of LREC 2010, May 2010, Malta.
    Harry Bunt, Jan Alexandersson, Jae-Woong Choe, Alex Chengyu Fang, Koiti Hasida, Volha Petukhova, Andrei Popescu-Belis, and David Traum:
    "ISO 24617-2: A semantically-based standard for dialogue annotation". In Proceedings of LREC 2012, May 2012, Istanbul.




    DIT-related publications
    Harry Bunt
    'The semantics of feedback. In Proceedings of SeineDial, the 2012 Workshop on the Semantics and Pragmatics of Dialogue, Paris, September 2012.
    Harry Bunt
    'Multifunctionality in dialogue.' Computer, Speech and Language 25 (2011), 225-245.
    Harry Bunt
    'The semantics of dialogue acts'. In Proceedings of the 9th International Conference on Computational Semantics (IWCS-9), Oxford, January 12-14, 2011, pp. 1-13.
    Volha Petukhova and Harry Bunt
    'Incremental dialogue act understanding'. In Proceedings of the 9th International Conference on Computational Semantics (IWCS-9), Oxford, January 12-14, 2011.
    Harry Bunt, Jan Alexandersson, Jean Carletta, Jae-Woong Choe, Alex Chengyu Fang, Koiti Hasida, Kyong Lee, Volha Petukhova, Andrei Popescu-Belis, Laurent Romary, Claudia Soria, and David Traum
    `Towards an ISO standard for dialogue act annotation' In Proceedings of LREC 2010, the Seventh International Conference on Language Resources and Evaluation, Malta, May 16-23, 2010.
    Harry Bunt
    'Interpetation and generation of dialogue with multidimensional context models.' In Anna Esposito (ed.) Toward Autonomous, Adaptive, and Context-Aware Multimodal Interfaces. Springer, Berlin, pp. 214-242. See also online version.
    Harry Bunt
    `A methodology for designing semantic annotation languages exploiting syntactic-semantic iso-morphisms.' In Proceedings of ICGL 2010, Second International Conference on Global Interoperability for Language Resources, Hong Kong, 18-20 January 2010.
    Volha Petukhova, Harry Bunt, and Andrei Malchanau
    'Empirical and theoretical constraints on dialogue act combinaations'. In Proceedings of the 14th International Workshop on the Semantics and Pragmatics of Dialogue (PozDial), Poznan, June 16-18, 2010.
    Volha Petukhova and Harry Bunt
    'Introducing communicative function qualifiers.' In Proceedings of ICGL 2010, Second International Conference on Global Interoperability for Language Resources, Hong Kong, January 2010.
    Volha Petukhova and Harry Bunt
    'Grounding by nodding.' In Proceedings of GESPIN 2009, Conference on Gestures and Speech in Interaction, Poznan, September 2009.
    Harry Bunt
    `Multifunctionality and multidimensional dialogue semantics'. In Proceedings of DiaHolmia 2009, (invited talk), Stockholm, June 2009.
    Volha Petukhova and Harry Bunt
    'Who's next? Speaker-selection mechanisms in multiparty dialogue'. In Proceedings of DiaHolmia 2009, 8th Internal Workshop on the Semantics and Pragmatics of Dialogue, Stockholm, June 2009.
    Harry Bunt
    'The DIT++ taxonomy for functional dialogue markup'. In Proceedings of the AAMAS 2009 Workshop "Towards a Standard Markup Language for Embodied Dialogue Acts" (EDAML 2009), Dirk Heylen, Catherine Pelachaud, Roberta Catizone, and David Traum, editors, Budapest, May 12, 2009.
    Volha Petukhova and Harry Bunt
    'The independence of dimensions in multidimensional dialogue act annotation'. tab In Proceedings of the NAACL 2009 conference, Boulder, Colorado, June 2009.
    Harry Bunt
    'Semantic Annotations as Complimentary to Underspecified Semantic Representations'. In Proceedings of the 8th International Conference on Computational Semantics (IWCS-8), Tilburg, January 7-9, 2009.
    Volha Petukhova and Harry Bunt
    'Towards a multidimensional semantics for discourse markers'. In Proceedings of the 8th International Conference on Computational Semantics (IWCS-8), Tilburg, January 7-9,2009
    Harry Bunt and Chwhynny Overbeeke
    `An Extensible, Compositional Semantics of Temporal Annotation.' In Proceedings of LAW-II, the Second Linguistic Annotation Workshop, Marrakech, Morocco, May 26-27, 2008.
    Jeroen Geertzen, Volha Petukhova, and Harry Bunt
    `Evaluating Dialogue Act Tagging with Naive and Expert Annotators.' In Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC 2008), Marrakech, Morocco, May 28-30, 2008.
    Harry Bunt and Chwhynny Overbeeke
    `Towards formal interpretation of semantic annotation.' In Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC 2008), Marrakech, Morocco, May 28-30, 2008.
    Volha Petukhova and Harry Bunt
    `LIRICS semantic role annotation: design and evaluation of a set of data categories.' In Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC 2008), Marrakech, Morocco, May 28-30, 2008.
    Harry Bunt
    `The Semantics of Semantic Annotation.' Invited paper presented at PACLIC-21, the 21st Pacific Asia Conference on Language, Information and Compuation, Seoul, Korea, November 2,. 2007. In (ed.) Proceedings of PACLIC-21, the 21st Pacific Asia Conference on Language, Information and Compuation, Seoul, Korea, November 1-3, 2007.
    Harry Bunt
    `Multifunctionality and Multidimensional Dialogue Act Annotation.' In E. Ahlsen et al. (ed.) Communication - Action - Meaning, A Festschrift to Jens Allwood. Gothenburg University Press, August 2007, pp. 237 -- 259.
    Harry Bunt and Roser Morante
    `The Weakest Link.' In V. Matousek and P. Mautner (2007) (eds.) Text, Speech and Dialogue. Lecture Notes in Artificial Intelligence (LNAI) 4629, Springer, Berlin.
    Harry Bunt, Roser Morante, Simon Keizer
    `An empirically based computational model of grounding in dialogue.' In Proceedings of the Eighth SIGDIAL Conference on Discourse and Dialogue (SIGDIAL 2007). Antwerp, 1-2 September, 2007, pp. 283-290.
    Jeroen Geertzen, Volha Petukhova, and Harry Bunt
    `A multidimensional approach to utterance segmentation and dilaogue act classification.' In Proceedings of the Eighth SIGDIAL Conference on Discourse and Dialogue (SIGDIAL 2007). Antwerp, 1-2 September, 2007, pp. 140-149.
    Roser Morante, Simon Keizer and Harry Bunt
    `Dialogue simulation and context dynamics for dialogue management.' In J. Nivre, H.-J. Kaalep, K. Muischnek, and M. Keit (eds) Proceedings of the 16th Nordic Conference on Computational Linguistics (NODALIDA 2007). Tartu, Estonia, pp. 310-317.
    Simon Keizer and Harry Bunt
    `Evaluating combinations of dialogue acts'. In Proceedings of the Eighth SIGDIAL Workshop on Discourse and Dialogue (SIGDIAL 2007), Antwerp, September, 2007, pp. 158-165.
    Roser Morante, Simon Keizer and Harry Bunt
    `A dialogue act based model for context updating.' In Proceedings of the Eleventh International Conference on the Semantics and Pragmatics of Dialogue (DECALOG 2007). Trento, 30 May - 3 July, 2007, pp. 9-16.
    Harry Bunt and Amanda Schiffrin
    `Interoperable concepts for dialogue act annotation.' In Proceedings of the Seventh International Workshop on Computational Semantics (IWCS-7). Tilburg, January 10-12, 2007, pp. 16-27.
    Volha Petukhova and Harry Bunt
    `A Multidimensional Approach to Multimodal Dialogue Act Annotation.' In Proceedings Seventh International Workshop on Computational Semantics (IWCS-7). Tilburg, January 10-12, 2007, pp. 142-153.
    Volha Petukhova, Harry Bunt and Amanda Schiffrin
    `Defining Semantic Roles.' In Proceedings Seventh International Workshop on Computational Semantics (IWCS-7). Tilburg, January 10-12, 2007, pp. 362-365.
    Jeroen Geertzen and Harry Bunt
    `Measuring annotator agreement in a complex hierarchical dialogue act scheme'. In Proceedings of SIGDIAL 2006, Sydney, July 15-16, 2006.
    Simon Keizer and Harry Bunt
    `Multidimensional dialogue management'. In Proceedings of SIGDIAL 2006, Sydney, July 15-16, 2006.
    Harry Bunt
    'Dimensions in Dialogue Act Annotation'. In Proceedings of the Fifth International Conference on Language Resources and Evaluation (LREC 2006). Genova, Italy, May 24-26, 2006.
    Harry Bunt and Amanda Schiffrin
    `Methodologial aspects of semantic annotation'. In Proceedings of the Fifth International Conference on Language Resources and Evaluation (LREC 2006). Genova, Italy, May 24-26, 2006.
    Jacques Terken, Hans van Dam and Harry Bunt
    `Cooperative assistance for human-system interaction'. In Proceedings of the 16th World Conference on Ergonomics (IEA2006), Maastricht, July 10-14, 2006.
    Harry Bunt
    `Mass Terms'. In Keith Brown (ed.) Encyclopaedia of Language and Linguistics, Second Edition. Elsevier, Amsterdam, pp. 5757-5760.
    Rieks op den Akker, Harry Bunt, Simon Keizer and Boris van Schooten
    `From Question Answering to Spoken Dialogue: Towards an Information Search Assistant for Interactive Multimodal Information Extraction'. In Proceedings of the Ninth European Conference on Speech Communication and Technology, Interspeech 2005, Lisbon, September 2005, pp. 2793-2797.
    Harry Bunt and Yann Girard
    `Designing an Open, Multidimensional Dialogue Act Taxonomy'. In Claire Gardent & Bertrand Gaiffe (eds) DIALOR'05, Proceedings of the Ninth International Workshop on the Semantics and Pragmatics of Dialogue. Nancy, June 9-11, 2005.
    Harry Bunt
    `A Framework for Dialogue Act Specification'.Paper presented at ISO_SIGSEM workshop Tilburg, January 10-11, 2005.
    Harry Bunt, Michael Kipp, Mark Maybury and Wolfgang Wahlster
    `Fusion and Coordination for Multimodal Interactive Information Presentation'. In: O. Stock and M. Zancanaro (eds) Multimodal Intelligent Information Presentation. Springer, Dordrecht 2005, pp. 325-339.
    Harry Bunt and Laurent Romary
    `Standardization in Multimodal Content Representation: Some Methodological Issues'.In: Proceedings of LREC 2004, Lisbon, Portugal, May 2004, pp. 2219-2222.
    Harry Bunt and Laurent Romary
    `Towards multimodal semantic representation'.In: Key-Sun Choi (ed.) Proceedings of LREC 2002 Workshop on International Standards of Terminology and Language Resourses Management, Las Palmas, Spain, 29 May 2002. ELRA, Paris, pp. 54-60.
    Leen Kievit, Paul Piwek, Robbert-Jan Beun and Harry Bunt
    `Multimodal Cooperative Resolution of Referential Expressions in the DenK System.'(pdf file).
    (Postscript file). In: H.C. Bunt & R.J. Beun (eds.) Cooperative Multimodal Communication , Lecture Notes in Artificial Intelligence 2155, Springer Verlag, Berlin, forthcoming October 2001, pp. 197-214.
    Harry Bunt
    `Dialogue pragmatics and context specification.'(ps file); `Dialogue pragmatics and context specification.'(pdf file). In: Harry Bunt and William Black (eds) Abduction, Belief and Context in Dialogue. Studies in Computational Pragmatics. John Benjamins, Amsterdam, 2000, Series Natural Language Processing, Volume 1, pp. 81-150.
    Harry Bunt and Willam Black
    `The ABC of Computational Pragmatics.'. In: Harry Bunt and William Black (eds) Abduction, Belief and Context in Dialogue. Studies in Computational Pragmatics. John Benjamins, Amsterdam, 2000, Series Natural Language Processing, Volume 1, pp. 1-46.
    Harry Bunt
    `Non-problems and social obligations in human-computer conversation'. In: Proceedings Third International Workshop on Human-Computer Conversation, Bellagio (Italy), July 2000.
    Harry Bunt, Rene Ahn, Robbert-Jan Beun, Teun Borghuis, & Cees van Overveld
    `The DenK architecture: a pragmatic approach to user interfaces.' Artificial Intelligence Review 8 (3), 1995, 431-445.
    Harry Bunt, Rene Ahn, Robbert-Jan Beun, Teun Borghuis, & Cees van Overveld
    `Multimodal Cooperation with the DenK System.' (postscript file) In: H.C. Bunt, R.J. Beun & T. Borghuis (eds.) Multimodal Human-Computer Communication. Sytems, Techniques and Experiments. Lecture Notes in Artificial Intelligence 1374, Springer Verlag, Berlin, pp. 39-67.
    Harry Bunt
    `Dynamic Interpretation and Dialogue Theory'. In: M.M. Taylor, D.G. Bouwhuis & F. Neel (eds.) The Structure of Multimodal Dialogue, Vol 2., Amsterdam: John Benjamins, 2000, pp 139-166.
    Harry Bunt
    `Dialogue control functions and interaction design'. In: R.J. Beun, M. Baker & M. Reiner (eds.) Dialogue in Instruction. Springer Verlag, Heidelberg, 1995, pp. 197 -- 214.
    Harry Bunt
    `Interaction management functions and context representation requirements'. In: S. LuperFoy, A. Nijholt, & G. Veldhuizen van Zanten (eds.) Dialogue Management in Nateral Language Systems. Proc. of 11th Twente Workshop on Language Technology, University of Twente, Enschede, June 1996, pp. 187 -- 198.
    Harry Bunt
    Context and Dialogue Control. Think Quarterly 3(1), 19-31.
    Harry Bunt
    `Belief Contexts in Human-Computer Dialogue'. In: D. Nauta, A. Nijholt & J. Schaake (eds.) Pragmatics in Language Technology. Proc. of 4th Twente Workshop on Language Technology, University of Twente, Enschede, June 1992, pp. 106 -- 114.
    Harry Bunt
    Information Dialogues as Communicative Action in Relation to User Modelling and Information Processing. In: M.M. Taylor, D.G. Bouwhuis & F. Neel (eds.) The Structure of Multimodal Dialogue, Vol. 1, Amsterdam: North-Holland, 1989, pp. 47-74.




    Different in release 5 from previous release (release 4, February 2010)

    DIT++ release 5 offers the same coverage as release 4, and is fully compatible with it: annotations using release 4 are easily converted into annotations using release 5 and vice versa. The changes (improvements!) have been inspired by the fact that the DIT++ taxonomy has been the basis for a proposed ISO standard for dialogue act annotation. In the course of defining the ISO standard proposal, some points were noted where the DIT++ taxonomy (release 4) could be improved. The most important of these improvements are the introduction of (1) communicative function qualifiers; and (2) rhetorical relations among dialogue acts.

    The use of function qualifiers allows a more principled treatment of the phenomenon that dialogue acts of a range of types can be qualified with respect to (un-)certainty, (un-)conditionality, partiality, and sentiment. As a result, the functions Uncertain Inform, Uncertain Answer, etc. have been eliminated as separate communicative functions, as well as indirect questions, indirect requests, etc.; these are often analysed more adequately as conditional forms of the corresponding dialogue acts.

  • Deleted:
    • Indirect questions and requests. The functions Indirect Set Question, Indirect Propositional Question, Indirect Alts Question, and Indirect Request have been removed. A functional segment which would be annotated usig DIT++ release 4 as having the function IndirectSetQuestion should now instead be annotated as having the function SetQuestion with qualifier Conditional. See ISO DIS 24617-2 (August 2010), Annex B for examples of how to do that using the Dialogue Act Markup Language DiAML.
    • Informs with a rhetorical function. The functions Elaborate, Exemplify, Justify, and Warning have been removed. Instead, the function Inform should now be used with the appropriate qualifier as value of the attribute for representing rhetorical relations. See ISO DIS 24617-2 (August 2010), Annex B for examples of how to do that using the Dialogue Act Markup Language DiAML.
    • Uncertain informs and answers: similar to the prevous two changes, the functions Uncertain Set Answer, Uncertain Propositional Answer, Uncertain Confirm, and Uncertain Disconfirm, have been removed. Instead, the qualifier should be used which adds the specification of a speaker's uncertainty.
    • Adaptation of 'belief' conditions in communicative function definitions: Related to the interpretation of the qualifiers "certain" and "uncertain", the condition that the sender of an answer believes his answer to be correct has been weakened a little, to the speaker "assuming" that this is the case. The attitude expressed by "assumes" is meant to cover both firm and uncertain belief, as expressed in release 4 by the terms "believes" and "weakly believes", respectively. The addition of the qualifier "certain" or the qualifier "uncertain" can then be understood as specializing the condition with "assumes" the one with "believes" or "weakly believes", respectively.

  • Other changes:
    • The function "Question" has been defined as a generalization of the three more specific question types that are defined. This may be useful in the case of questions with a very elliptic formulation (such as Well?), of which the specific type may be hard to determine.
    • The function "Answer" has been introduced, replacing the functions "Set Answer" and "Propositional Answer". This is because it is often only possible to determine the type of answer by looking at the type of question that it answers. This makes the distinction rather useless; moreover, an adequate annotation of answer functions to dialogue segments should include the indication of which question is answered, which makes it redundant to differentiate types of answers. See ISO DIS 24617-2, Annex B for examples of how to do this annotation in DiAML.
    • The function "Alts-question" has been renamed "Choice Question".
    • The function Answer has been defined in such a way that answers (of all kinds) are now specializations of Inform.
    • The definitions of some communicative functions have been reformulated slightly in order to be identical with the corresponding function definition in ISO DIS 24617-2. The DIT++ functions in this release form a superset of those in the proposed ISO standard.




    Last modified: August 2010
    <harry.bunt@uvt.nl>