Chapter+Eight

=Chapter 8 – Scenarios= //8.1 Introduction// - Stories about people undertaking activities in contexts using technologies - Important approach to the design of interactive systems in the 20th Century - Carroll argues that scenarios are effective at dealing with 5 key problems of design 1. External factors (time, lack of resources, existing designs) 2. Single design impacts many areas 3. Technology changes at a rapid pace so generic solutions are useless. 4. Importance of reflection and action in design 5. Slippery nature of design problems - Figure 8.1 on page 193 shows a diagram of Challenges and Approaches in scenario-based design - Rarely one design that fixes all problems - Claims analysis: identify key features of a scenario and lists good and bad aspects of the design

//8.2 Scenarios throughout design// - Useful in: (5 key stages of interactive system design) 1. Requirements work 2. Prototyping 3. Envisionment 4. Evaluation 5. Conceptual design 6. Physical design - 4 types of scenarios 1. User stories § Real world experiences of people 2. Conceptual scenarios § More abstract descriptions 3. Concrete scenarios § Generated from abstract scenarios by adding specific design decisions 4. Use cases § Once concrete scenario process is completed these can be represented as use cases - Help to determine problems people are having

User Stories - Real world ideas or experiences - Rich in context

Conceptual Scenarios - More abstract than user stories - Similar stories are combined together - Useful for generating ideas and for understanding the requirements for the system

Concrete Scenarios - Each conceptual scenario may generate a lot of concrete scenarios - Often identify problems that exist only under certain circumstances <span style="font-family: 'Arial','sans-serif';">- Begin to dictate particular interface design and functions <span style="font-family: 'Arial','sans-serif';">- Useful for prototyping, envisioning design ideas and for evaluation <span style="font-family: 'Arial','sans-serif';">- Not a clear break between conceptual and concrete <span style="font-family: 'Arial','sans-serif';">- The more specific, the more concrete

Use Cases <span style="font-family: 'Arial','sans-serif';">- Describes interaction between people and devices <span style="font-family: 'Arial','sans-serif';">- How system is used <span style="font-family: 'Arial','sans-serif';">- Describes what people do and what the system does <span style="font-family: 'Arial','sans-serif';">- Design issues are resolved and a set of concrete scenarios are used as basis for design <span style="font-family: 'Arial','sans-serif';">- Can be presented in the form of abstract diagrams to detailed “pseudo code” //8.3 Documenting scenarios// <span style="font-family: 'Arial','sans-serif';">- Structure designed to organize scenarios <span style="font-family: 'Arial','sans-serif';">- PACT framework used to critique scenarios <span style="font-family: 'Arial','sans-serif';">- Must consider assumptions <span style="font-family: 'Arial','sans-serif';">- Important to provide rich context

Cross-referencing Scenario Types <span style="font-family: 'Arial','sans-serif';">- Cross-reference user stories to conceptual scenarios through concrete examples and finally to the use cases //8.4 A scenario-based design method// <span style="font-family: 'Arial','sans-serif';">- Method for formalizing the different types of design scenarios <span style="font-family: 'Arial','sans-serif';">- Figure 8.5 on page 204 is an example of Overall scenario-based design method <span style="font-family: 'Arial','sans-serif';">- Notice relationship between specifying design constraints and use of scenarios

Requirements and problems <span style="font-family: 'Arial','sans-serif';">- Issues and difficulties arise that help designer to determine requirements, qualities or functions of new system

Scenario Corpus <span style="font-family: 'Arial','sans-serif';">- Want to develop a representative and carefully thought-through set, or corpus, of scenarios <span style="font-family: 'Arial','sans-serif';">- Designers gather a lot of information through the use of scenarios o Some detailed and some not <span style="font-family: 'Arial','sans-serif';">- Designer pulls information and experiences together to create system <span style="font-family: 'Arial','sans-serif';">- Rationale for developing corpus of scenarios is to uncover ‘dimensions’ of design situation and to demonstrate different aspects of those dimensions <span style="font-family: 'Arial','sans-serif';">- Needs to cover all main functions of system and the events that trigger the functions <span style="font-family: 'Arial','sans-serif';">- Might consist of several scenarios depending on complexity of domain

Conceptual Model <span style="font-family: 'Arial','sans-serif';">- Object or data model results from process of conceptual modeling <span style="font-family: 'Arial','sans-serif';">- Shows main objects in the system, their attributes and the relationships that exist between them <span style="font-family: 'Arial','sans-serif';">- Very important part of interactive systems design that is often overlooked <span style="font-family: 'Arial','sans-serif';">- Well-designed conceptual model = easier to design <span style="font-family: 'Arial','sans-serif';">- Forms the basis of the information architecture of a system

Design Language <span style="font-family: 'Arial','sans-serif';">- Consists of set of standard patterns of interaction and all physical attributes of a design o Colours o Shapes o Icons <span style="font-family: 'Arial','sans-serif';">- Brought together with conceptual actions and objects and the ‘look and feel’ of design is completed <span style="font-family: 'Arial','sans-serif';">- Defines key elements of the design o Colour o Style o Types of buttons o Sliders o Widgets o Principles and rules for putting them together <span style="font-family: 'Arial','sans-serif';">- Consistent design language = more user-friendly