Lecture 3 Flashcards
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
Task Descriptions: (Use Cases). What for?
• Focus on lower-level user-system interaction rather than the user’s task itself
• Assume interaction with a system
• Assumedetailedunderstandingoftheinteraction
• Include
- Normal course, i.e. the set of actions that the
- analyst believes to be most commonly performed
- Alternative courses (when there is more than one option)
Essential Use Cases?
— abstract away from the details
— does not have the same assumptions as use cases (e.g., the kind of interaction)
— An essential use cases is a structured narrative consisting of three parts:
- a name that expresses the overall user intention
- a stepped description of user actions,
- a stepped description of system responsibility
Make a Example Essential Use Case for Holiday Planner
(see page 62 slide 3)
Task Descriptions/analysis?
- Are often often used to envision new systems or devices
- Task analysis is used mainly to investigate an existing situation
- It is important not to focus on superficial activities (what are people trying to achieve? Why are they trying to achieve it? How are they going about it?)
Obs. there are many techniques but the most popular is Hierarchical Task Analysis (HTA)
Hierarchical Task Analysis?
- Involves breaking a task down into subtasks, then sub-sub-tasks and so on. These are grouped as plans which specify how the tasks might be performed in practice
- HTA focuses on physical and observable actions, and includes looking at actions not related to software or an interaction device
- Start with a user goals which is examined and the main tasks for achieving it are identified
Give example of HTA in order to borrow a book from the library
s.66 (föreläsning 3)
Example Hierarchical Task Analysis (Graphical)
s.67 (föreläsning 3)
Which are the most commonly-used techniques for data gathering? (7)
- Questionnaires
- Interviews
- Focus groups
- Direct observation
- Studying documentation
- Researching similar products
- Contextual inquiry
