S. Wilson and P. Johnson 1 CADUI' June FUNDP Namur Bridging the Generation Gap: From Task Models to User Interface Designs Stephanie Wilson and Peter Johnson Department of Computer Science Queen and Westfield College University of London

S. Wilson and P. Johnson 2 CADUI' June FUNDP Namur Or... Design Guidelines and Task-Based Design

S. Wilson and P. Johnson 3 CADUI' June FUNDP Namur Guidelines  Directing principles to be followed to achieve a particular effect in some situation  Expressed in different forms  Flexibility...

S. Wilson and P. Johnson 4 CADUI' June FUNDP Namur Flexibility in Guidelines Anybody out there?

S. Wilson and P. Johnson 5 CADUI' June FUNDP Namur Guidelines in User Interface Design  Directing principles to be followed during design or evaluation of a system to increase its usability  General, abstract and broad in application or Specific, concrete and narrow in application  Constructive or evaluative  Emerge from theory or practice  Largely concerned with later stages of design

S. Wilson and P. Johnson 6 CADUI' June FUNDP Namur Overview  Guidelines and user interface design  Task-based design  Guidelines in task-based design:  Analysing work tasks  Envisioning work tasks  Designing interaction  Conclusions

S. Wilson and P. Johnson 7 CADUI' June FUNDP Namur Task-Based Design Existing task description(s) Envisioned task description Interface design Analysis of work Design of work Design of interaction Method Models Processes Tools

S. Wilson and P. Johnson 8 CADUI' June FUNDP Namur Guidelines in Task-Based Design  Focus on processes  Developing practical guidance  Motivated by experience Task analysis guidelines Abstract UI model (A) Existing work tasks Envisioned work tasks (B) Envisioned work tasks (A) Interface design (A) Abstract UI model (B) Interface design (B) Guidelines for envisioning work Guidelines for designing interaction Style guides, colour guides, typography etc

S. Wilson and P. Johnson 9 CADUI' June FUNDP Namur Analysing Work Tasks  Analysing and modelling Specific Tasks  Modelling Composite Tasks

S. Wilson and P. Johnson 10 CADUI' June FUNDP Namur Specific Tasks  Identify characteristics of specific tasks first  Use more than one data collection technique  Analyse many different users performing each task  Identify all variations and individual differences in tasks

S. Wilson and P. Johnson 11 CADUI' June FUNDP Namur Composite Task Models  Produce a composite task model from each task description for the same goal  Resolve conflicting descriptions  Identify optional aspects of a task  Identify compulsory aspects of a task  Identify commonalities of behaviour and objects  Identify constraints and dependencies  Identify different objects and typical objects

S. Wilson and P. Johnson 12 CADUI' June FUNDP Namur Envisioning Future Work Tasks  Influences: existing task descriptions, problem statement, requirements, design ideas, design constraints  Scoping the design  Improving the work

S. Wilson and P. Johnson 13 CADUI' June FUNDP Namur Scoping the Design  Identify tasks that can be avoided or are unnecessary  Identify tasks that can be carried out by system  Identify tasks that can only be carried out by user  Identify where user will interact with system to perform a task  Introduce any new tasks

S. Wilson and P. Johnson 14 CADUI' June FUNDP Namur Improving the Work  Identify where sequences of activities can be made easier to perform  Create more powerful objects by combining individual objects  Restructure the task to bring together information required at the same point in the task  Ensure that safety and security procedures are supported

S. Wilson and P. Johnson 15 CADUI' June FUNDP Namur Creating an Interface Design  Influences: task descriptions, requirements, design ideas, design constraints, design guidelines  Task influences:  Task decomposition information  Action and object information  Sequencing information

S. Wilson and P. Johnson 16 CADUI' June FUNDP Namur Task Decomposition Information  Reflect the goal, sub-goal and action decomposition in the interface structure  Group interface components that support closely related parts of the task  Group components either spatially or temporally  Let the lowest level of task decomposition (actions) be the strongest determinant of interface structure

S. Wilson and P. Johnson 17 CADUI' June FUNDP Namur Task Actions and Objects  Use task objects to identify information to be displayed and/or manipulated  Use task actions to identify commands  Use action-object groupings to determine the ways in which information can be manipulated  Support simple objects, and the actions applied to them, by standard widgets  Support complex task objects by a group of standard widgets or by specialised widgets

S. Wilson and P. Johnson 18 CADUI' June FUNDP Namur Task Sequence Information Task Sequence Information  Reflect task sequencing in the dialogue structure  Do not violate task sequencing in the interface design ...But constraints can be relaxed in situations where safety conditions will not be contravened

S. Wilson and P. Johnson 19 CADUI' June FUNDP Namur Conclusions  Importance of design processes in task-based and model-based approaches to design  Practical guidance for designers  Implications for tools and future work