From Task-Oriented to Goal-Oriented Web Requirements Analysis
Davide Bolchini , John Mylopoulos
TEC lab – University of Lugano, Switzerland
davide.bolchini@lu.unisi.ch
Department of Computer Science - University of Toronto, Canada
jm@cs.toronto.edu
Abstract
Task analysis has been used traditionally in HCI and
CSCW to define requirements for user interfaces, web-
based or otherwise. This paper argues that a shift of
paradigm is needed in web engineering from task-
oriented to goal-oriented approaches for designing
applications delivering a quality user experience and
achieving the objectives of the stakeholders. Task models
focus on fine-grained and precisely defined user needs,
thereby risking a commitment to premature design
decisions. Moreover, since task analysis focuses on users
doing things with the system, tasks do not capture the
goals of other stakeholders who are not users. Goal-
oriented methods, on the other hand, provide specific
support for coping with high-level users’ and
stakeholders’ goals, facilitates the exploration of design
alternatives and the definition of requirements at a
suitable level of abstraction. As such, goal-based
techniques are more suitable for early stages of
requirements analysis; task models can be used for later
stages, such as detailed interaction design and usability
evaluation. The paper conducts a detailed comparison of
task- and goal-analysis design techniques, using an
ongoing project for a museum website to illustrate the two
techniques and their relative strengths.
Keywords: requirements analysis, stakeholders, goal,
task, website design.
1. Introduction
Let us consider the following scenario. An Italian
tourist just arrived in Paris with his family has four days to
spend in the French capital. He does not want to miss
visiting one of the most famous museums in the world and
thus manages to find an Internet connection to access the
museum website. What would he access the website for?
Probably, when asked, even the tourist would not be able
to articulate a precise objective for visiting the site: he
might just want to see what the museum has to offer, get
an idea of how much is there to visit, understand the
variety of the collection hosted, check the visiting hours,
gather the elements to plan a visit or maybe he would just
be confirmed in the belief that the museum is really worth
visiting.
On one hand, a nebulous mix of expectations, ill-
defined goals, generic interests and practical needs
informs the attitude by which the user will approach the
website. On the other, the museum communication
department basically conceived the site with the aim of
maintaining the prestigious image of the museum all over
the world and not disappointing the expectations of its
worldwide audience. The museum needs to communicate
the well-organized nature of the institution, as well as its
proud history and fabulous collection.
Under these circumstances, what are the chances that
the user experience will be satisfactory? What are the
chances that the communication goals of the museum will
be achieved?
Analysts and web designers have to cope with such
complexity arising both from the user and the main
stakeholders’ side, in order to design solutions delivering
an effective user experience and meeting the
communication objectives. Thus, analysts and designers
need systematic techniques to achieve a healthy balance
between the consideration of users’ and stakeholders’
requirements in the development of a website.
With regards to the user side, the heterogeneous family
of task-based techniques represents the dominant
paradigm for the analysis of user requirements. Basically,
the question that task models try to answer is: What will
the user do with the website? User tasks are envisioned
targets of achievement and courses of actions the user
might want to accomplish on the website. In this user-
centered perspective, tasks are analyzed and decomposed
providing an input for the design activity.
A basic premise of Requirements Engineering
(hereafter RE) is that all stakeholders, not just users, need
to be consulted and accommodated by the system-to-be.
Moreover, goal-based RE techniques do so by identifying
and analyzing high-level stakeholder goals. Basically, the
question that goal models try to answer is: What are the
goals of the stakeholders of the website? Goals are
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Proceedings of the Fourth International Conference on Web Information Systems Engineering (WISE’03)
0-7695-1999-7/03 $17.00 © 2003 IEEE