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Identifying needs and establishing

requirements

7.1 Introduction
7.2 What, how, and why?
7.2.1 What are we trying to achieve in this design activity?
7.2.2 How can we achieve this?
7.2.3 Why bother? The importance of getting it right
7.2.4 Why establish requirements?
7.3 What are requirements?
7.3.1 Different kinds of requirements
7.4 Data gathering
7.4.1 Data-gathering techniques
7.4.2 Choosing between techniques
7.4.3 Some basic data-gathering guidelines
7.5 Data interpretation and analysis
7.6 Task description
7.6.1 Scenarios
7.6.2 Use cases
7.6.3 Essential use cases
7.7 Task analysis
7.7.1 Hierarchical Task Analysis (HTA)

7.1 Introduction

An interaction design project may aim to replace or update an established system,
or it may aim to develop a totally innovative product with no obvious precedent.
There may be an initial set of requirements, or the project may have to begin by
producing a set of requirements from scratch. Whatever the initial situation and
whatever the aim of the project, the users' needs, requirements, aspirations, and
expectations have to be discussed, refined, clarified, and probably re-scoped. This
requires an understanding of, among other things, the users and their capabilities,
their current tasks and goals, the conditions under which the product will be used,
and constraints on the product's performance.