Scenarios, Stories, Use Cases: Through the Systems Development Life-Cycle

CHAPTER 10

THE ROLE OF SCENARIOS IN CONTEXTUAL DESIGN: FROM USER OBSERVATIONS TO WORK REDESIGN TO USE CASES

Karen Holtzblatt

InContext Enterprises Inc., Maryland, USA

CONTEXTUAL DESIGN (CD) is a full customer-centered design process for system and product design, providing explicit steps and deliverables from initial discovery through system specification. Contextual Design is used to characterize a market or population, identify product and system concepts, and work out the details of the specific system definition. Contextual Design uses customer data throughout the process to drive design decisions. User scenarios and scenario-based reasoning is central to the CD process. But for good design, scenario-based reasoning must be alternated with model-based reasoning. In this chapter we talk about how customer data, scenarios, and models are used within the CD process to produce designs that work for people.

At its core, a scenario is a sequence of steps that defines a task performed to achieve an intent. Life is lived in a sequence, one moment at a time. When a person performs a task we observe sequential action. Although a person might consider multiple options before choosing, “consideration” is a step in a sequence. When we collect task data from multiple people, or even multiple instances of a task from the same person, we start to identify choice points or strategies. But we will only see this structure in the work¹ when we step back from the actual activities observed and ...