What is design?
• Achieving Goals within Constraints • Trade-off
– Which goals or constraints can be relaxed so that others can be met.
• Understand computers
– Limitations, capacities, tools, platforms
• Understand people
– Psychological, social aspects, human error
What is User-Centered Design?
Based on:
- Early focus on users and tasks: directly studying cognitive,
behavioural, anthropomorphic & attitudinal characteristics
- Empirical measurement: users’ reactions and performance to scenarios, manuals, simulations & prototypes are observed, recorded and analysed
- Iterative design: when problems are found in user testing in any stage, fix them and carry out more tests
User-centered design emphasizes on:
(1) solving the right problem, and (2) solving it in a way that meets human needs and capabilities
Four Basic Activities in the design process
– Identifying needs and establishing requirements
(describe and get to know users, describe and analyze tasks, produce requirments)
- Developing alternative sesign
Building interactive version of the design
- Evaluating designs
Identify Needs and Establish Requirements. 3 questions?
What, How, and Why?
Identify Needs and Establish Requirements: what?
Two aims:
- Understand as much as possible about the users, tasks, contexts
- Produce a stable set of requirements
Identify Needs and Establish Requirements: How? (4)
- Data gathering activities
- Data analysis activities
- Expression as ‘requirements’ - All of above is iterative
Identify Needs and Establish Requirements: Why?
“finding and fixing a software problem after delivery is often 100 times more expensive than finding and fixing it during the requirements and design phase.”
- What do users want? What do users ‘need’?
• Vitamin vs. painkiller
Questions to Ask When Establishing Requirements: (4)
- Who is the target user?
- What challenges do they face?
- What current strategies do they use to address these challenges?
- What values influence what they see as an acceptable technology?
Establishing Requirements (4 steps)
• Step1: get all the ideas
– What goals and capabilities would this product support?
• Step 2:group logically related ideas under a business goal
– E.g., a high-level goal of “provide better ongoing and active customer service and support without having to go on-site” can be achieved via a collection of lower-level goals/functions such as proactive services, faster responses to requests, etc.
• Step 3: prioritize
– Focus on fulfilling the core critical goals
– E.g., built-in emails? social networking capabilities?
• Step 4: document the results
Requirement Statement?
A requirement is a statement about an intended product that specifies what it should do or how it should perform.
Different Kinds of Requirements
Functional and non-functional
Data requirements and Environmental
Functional requirements?
- What the system should do
Non-functional requirements?
What constraints there are on the system and its development
Data requirement?
What kind of data need to be stored?
How till they be stored? (database?)
Environmental requirements?
― physical environment
― social environment
― organisational environment ― technical environment
Data Gathering for Requirements (4 parts)
• Interviews
Explore issues
• Focus group
Gain a consensus view
• Questionnaires
Get initial responses
• Observation
Understand the nature of tasks and contextsWhy is it good to study documentation while gathering data for Requirements? (3)
- Procedures and rules are often written down in manuals
- Good source of data about the steps involved in an activity, and any regulations governing a task
- Good for understanding legislation, and getting background information
What is a Context Inquiry (While Gathering Data for requirements)?
• An approach that emerged from the ethnographic approach
- Context: see workplace & what happens
- Partnership: user and developer collaborate
- Interpretation: observations interpreted by user and developer together
4 questions that should be answered will gathering data (for requirements)?
- Who is the target user?
- What challenges do they face?
- What current strategies do they use to address these challenges?
- What values influence what they see as an acceptable technology?
Modelling Users =
Personas
Modelling Users: Personas. (5 points)
- Capture user characteristics
- Not real people
- Should not be idealised
- Bring them to life with a name, characteristics, goals, personal background
- Develop multiple (3/5)
Task Descriptions: (Scenarios). What for?
Bridging the gap between user research and design
Scenarios. (3 points)
- An informal narrative story, simple, “natural”, personal, not generalizable
- Describe human activities or tasks in a story that allows exploration and discussion of context, needs, and requirements
- Does not explicitly describe the use of software or other technological support to achieve a task
