Task Models describe how to perform activities to reach users' goals. Task models represent the intersection between user interface design and more systematic approaches. Task models can be represented at various abstraction levels. When designers want to specify only requirements regarding how activities should be performed, they consider only the main high-level tasks. On the other hand, when designers aim to provide precise design indications then the activities are represented at a small granularity, thus including aspects related to the dialogue model of a user interface (which defines how system and user actions can be sequenced). In this paper a comparative analysis of selected models involving multiple users in an interaction is provided in order to identify concepts which are underexplored in today’s multi-user interaction task modeling. This comparative analysis is based on three families of criteria: information criteria, conceptual coverage, and expressive¬ness. Merging the meta-models of the selected models enables to come up with a broader meta-model that could be instantiated in most situations involving multi-user interaction, like workflow information systems, CSCW.

1. A comparative analysis of task modeling
notations
Dra. Josefina Guerrero García
Dr. Juan Manuel González Calleros
Dr. Jean Vanderdonckt *
Facultad de Ciencias de la Computación
Benemérita Universidad Autónoma de Puebla
*Université catholique de Louvain
Email: jguerrero@cs.buap.mx
juan.gonzalez@cs.buap.mx

2. Outline
• Introduction
• Overview of task models
• A multi-user interaction meta-model
• Conclusion

3. Introduction (1/4)
• Task models describe how to perform activities
to reach user´s goals.
• Task models represent the intersection between
user interface design and more systematic
approaches.
• A number of task modeling notations have been
developed in HCI communities, often with
different goals and different strengths.

4. Introduction (2/4)
Task Modeling are the
hearth of Model Driven
Development of UIs
Final User Interface (FUI)
WindowWindow
Concrete User Interface
(CUI)
AIC
facet=control
AbstractIndividual
Container
Abstract User Interface
(AUI)
textInputtextInput buttonbutton buttonbutton
AIC
facet=control
AIC
facet=control
Task & Domain (T&D)

5. Introduction (3/4)
• A comparative analysis of selected models
involving multiple users interaction is provided
in order to identify concepts which are
underexplored in today´s multiuser interaction
task modeling.

6. Introduction (4/4)
• The goals are:
▫ To provide a conceptual understanding of the
most significant models involving multiple users
and their related concepts.
▫ To establish semantic mappings between the
different models so as to create a transversal
understanding of their underlying concepts
independently of their peculiarities.
▫ To rely on these semantic mappings to develop a
multi-user model editor that accommodates any
type of input.

7. Overview of task models (1/7)
• Our method for uniforming task models consists
of four major steps:
1. selection of individual task models,
2. identification of the concepts within each model,
3. representation of those concepts into a meta-
model,
4. consolidation of these meta-models into one
single meta-model (called multi-user interaction
model).

8. Overview of task models (2/7)
• The following criteria were used:
▫ The task models should be integrated in a
development methodology as a core or side
component and tool supported.
▫ The task models should be widespread and
accepted within the Human-Computer Interaction
(HCI) community.
▫ The selected models should be supported by
theoretical studies to assess their soundness and
experimental studies for effective case studies.

9. Overview of task models (3/7)
• Each model was decomposed into constituent
concepts using an entity-relationship method
and UML representation.
• A syntactical uniforming has been conducted to
provide a single way of referring to different
concepts where possible.
• For concepts having different definitions a
semantic uniforming is needed (semantic
mappings between concepts having different
aims and scopes).

10. Overview of task models (4/7)
• To maximize the semantic scope of the
uniformed task meta-model, the union of the
concepts present in each particular task meta-
models was preferred rather than the
intersection.
• We use Separation of concern principle, which
assumes that only concepts relevant to a similar
domain of discourse should be kept in a
particular model, thus avoiding mixing different
concepts into a single model.

11. Overview of task models (5/7)
• Task modeling notations reviewed
AMBOSS GTA (Groupware Task Analysis)
ANSI/CEA-2018 HTA (Hierarchical Task Analysis)
CTT (ConcurTaskTree) TKS (Task Knowledge Structure)
Diane+ TOOD (Task Object-Oriented
Description)
GOMS UsiXML

12. • ANSI/CEA-2018 meta-model
Task Model
+about: URI
Binary
Task
+id: ID
+description: string
+precondition: string
+postcondition: string
input
+name: string
+type: string
+modified: string
output
+name: string
+type: string
concept
+verb: string
step
+name: string
+task: string
+requires: string
+ordered: boolean
applicable binding
+slot: string
+value: string
TaskModelScript
+task: QName
+model: URI
+init: boolean
+platform: token
+deviceType: token
+applicable: string
Task Relationship
sequential Choice
role
+name: string
+type: ceaDataType
+slot: ceaSlotName
optional iteration
Unary
TemporaryRelationships
agent
theme
instrument
location
Decomposition
Concurrency
1..* 1..*
TaskScript
+init: boolean
+platform: token
+deviceType: token
+applicable: string
1..*
0..*
0..*
0..*
Overview of task models (6/7)

13. • CTT meta-model
TaskModel
Task
+id: string
+name: string
+type: string
+category: string
+frequency: string
+platform: string
+description: string
+precondition: string
+duration: time
TaskRelationshipsRole
+id: string
+name: string
TemporalRelationshipsDecomposition
Object
+name: strig
+type: string
+class: string
+accesMode: string
+cardinality: string
Action
+id: string
+name: string
+type: string
Binay Unary
Choice OrderIndependence Inerleaving
Synchronization
Disabling
SuspendResume
SequentialEnabling
SequentialEnablingInformqtionPassingCooperative
1..* 1..*
Optional Iterative
0..1
0..*
1..*
1..*
Overview of task models (7/7)

14. Task Modeling Operators

15. CTT
Diane+
AMBOSS
ANSI/C
EA-2018
GOMS
GTA
HTA
TKS
TOOD
UsiXML
Abstraction
Multi-user
interaction
meta-model
UsiXML
MDDUI:
A multi-user interaction meta-model (1/8)
GUI
AR
3DUI
VocalUI
HapticUI
Physical
UI
Multimo
dalUI

16. None
Moderate
High
Dynamicity
Color is useful for identifying
the concepts used in the
design and implementation of
the workflow editor

17. A multi-user interaction meta-model (3/8)

18. Marco de Referencia
A multi-user interaction meta-model (4/8)

19. Paso 1
A multi-user interaction meta-model (5/8)

20. Paso 2
A multi-user interaction meta-model (6/8)

21. Paso 3
A multi-user interaction meta-model (7/8)

22. A multi-user
interaction
meta-model (8/8)

23. Conclusion (1/2)
• Task models show a variety of concepts and
relationships, we analyzed them in order to
identify concepts which are underexplored in
today´s multi-user interaction task modeling.
• After the analysis of task models, a multi-users
interaction meta-model was generated in order
to cover the principal characteristics required to
work with multiplicity entities playing a role.

24. Conclusion (2/2)
• Our meta-model tries to cover the principal aspect
required to support group work, it include
process, tasks, task operators (including
collaboration
relationship), actions, objects, resources, groups (as
an attribute), organizational
units, jobs, agendas, goals and rules (both of them
as attributes).
• In a future work, we would like to integrate in our
comparative analysis other task models that are
focused on multi-users interaction. Also, it would be
interested to integrate a task analysis part, until now

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27. Contact
Dra. Josefina Guerrero-García jguerrero@cs.buap.mx
Dr. Juan Manuel González-Calleros juan.gonzalez@cs.buap.mx
@Juan__Gonzalez